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NAME

Chart - A class for writing Excel Charts.

SYNOPSIS

To create a simple Excel file with a chart using Excel::Writer::XLSX:

    #!/usr/bin/perl

    use strict;
    use warnings;
    use Excel::Writer::XLSX;

    my $workbook  = Excel::Writer::XLSX->new( 'chart.xlsx' );
    my $worksheet = $workbook->add_worksheet();

    # Add the worksheet data the chart refers to.
    my $data = [
        [ 'Category', 2, 3, 4, 5, 6, 7 ],
        [ 'Value',    1, 4, 5, 2, 1, 5 ],

    ];

    $worksheet->write( 'A1', $data );

    # Add a worksheet chart.
    my $chart = $workbook->add_chart( type => 'column' );

    # Configure the chart.
    $chart->add_series(
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$B$2:$B$7',
    );

    __END__

DESCRIPTION

The Chart module is an abstract base class for modules that implement charts in Excel::Writer::XLSX. The information below is applicable to all of the available subclasses.

The Chart module isn't used directly. A chart object is created via the Workbook add_chart() method where the chart type is specified:

    my $chart = $workbook->add_chart( type => 'column' );

Currently the supported chart types are:

Chart subtypes are also supported in some cases:

    $workbook->add_chart( type => 'bar', subtype => 'stacked' );

The currently available subtypes are:

    area
        stacked
        percent_stacked

    bar
        stacked
        percent_stacked

    column
        stacked
        percent_stacked

    scatter
        straight_with_markers
        straight
        smooth_with_markers
        smooth

    radar
        with_markers
        filled

More charts and sub-types will be supported in time. See the "TODO" section.

CHART METHODS

Methods that are common to all chart types are documented below. See the documentation for each of the above chart modules for chart specific information.

add_series()

In an Excel chart a "series" is a collection of information such as values, X axis labels and the formatting that define which data is plotted.

With an Excel::Writer::XLSX chart object the add_series() method is used to set the properties for a series:

    $chart->add_series(
        categories => '=Sheet1!$A$2:$A$10', # Optional.
        values     => '=Sheet1!$B$2:$B$10', # Required.
        line       => { color => 'blue' },
    );

The properties that can be set are:

  • values

    This is the most important property of a series and must be set for every chart object. It links the chart with the worksheet data that it displays. A formula or array ref can be used for the data range, see below.

  • categories

    This sets the chart category labels. The category is more or less the same as the X axis. In most chart types the categories property is optional and the chart will just assume a sequential series from 1 .. n.

  • name

    Set the name for the series. The name is displayed in the chart legend and in the formula bar. The name property is optional and if it isn't supplied it will default to Series 1 .. n.

  • line

    Set the properties of the series line type such as colour and width. See the "CHART FORMATTING" section below.

  • border

    Set the border properties of the series such as colour and style. See the "CHART FORMATTING" section below.

  • fill

    Set the fill properties of the series such as colour. See the "CHART FORMATTING" section below.

  • marker

    Set the properties of the series marker such as style and colour. See the "SERIES OPTIONS" section below.

  • trendline

    Set the properties of the series trendline such as linear, polynomial and moving average types. See the "SERIES OPTIONS" section below.

  • smooth

    The smooth option is used to set the smooth property of a line series. See the "SERIES OPTIONS" section below.

  • y_error_bars

    Set vertical error bounds for a chart series. See the "SERIES OPTIONS" section below.

  • x_error_bars

    Set horizontal error bounds for a chart series. See the "SERIES OPTIONS" section below.

  • data_labels

    Set data labels for the series. See the "SERIES OPTIONS" section below.

  • points

    Set properties for individual points in a series. See the "SERIES OPTIONS" section below.

  • invert_if_negative

    Invert the fill colour for negative values. Usually only applicable to column and bar charts.

  • overlap

    Set the overlap between series in a Bar/Column chart. The range is +/- 100. Default is 0.

        overlap => 20,

    Note, it is only necessary to apply this property to one series of the chart.

  • gap

    Set the gap between series in a Bar/Column chart. The range is 0 to 500. Default is 150.

        gap => 200,

    Note, it is only necessary to apply this property to one series of the chart.

The categories and values can take either a range formula such as =Sheet1!$A$2:$A$7 or, more usefully when generating the range programmatically, an array ref with zero indexed row/column values:

     [ $sheetname, $row_start, $row_end, $col_start, $col_end ]

The following are equivalent:

    $chart->add_series( categories => '=Sheet1!$A$2:$A$7'      ); # Same as ...
    $chart->add_series( categories => [ 'Sheet1', 1, 6, 0, 0 ] ); # Zero-indexed.

You can add more than one series to a chart. In fact, some chart types such as stock require it. The series numbering and order in the Excel chart will be the same as the order in which they are added in Excel::Writer::XLSX.

    # Add the first series.
    $chart->add_series(
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$B$2:$B$7',
        name       => 'Test data series 1',
    );

    # Add another series. Same categories. Different range values.
    $chart->add_series(
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$C$2:$C$7',
        name       => 'Test data series 2',
    );

It is also possible to specify non-contiguous ranges:

    $chart->add_series(
        categories      => '=(Sheet1!$A$1:$A$9,Sheet1!$A$14:$A$25)',
        values          => '=(Sheet1!$B$1:$B$9,Sheet1!$B$14:$B$25)',
    );

set_x_axis()

The set_x_axis() method is used to set properties of the X axis.

    $chart->set_x_axis( name => 'Quarterly results' );

The properties that can be set are:

    name
    name_font
    name_layout
    num_font
    num_format
    line
    fill
    min
    max
    minor_unit
    major_unit
    interval_unit
    crossing
    reverse
    position_axis
    log_base
    label_position
    major_gridlines
    minor_gridlines
    visible
    date_axis
    text_axis
    minor_unit_type
    major_unit_type
    display_units
    display_units_visible

These are explained below. Some properties are only applicable to value or category axes, as indicated. See "Value and Category Axes" for an explanation of Excel's distinction between the axis types.

  • name

    Set the name (title or caption) for the axis. The name is displayed below the X axis. The name property is optional. The default is to have no axis name. (Applicable to category and value axes).

        $chart->set_x_axis( name => 'Quarterly results' );

    The name can also be a formula such as =Sheet1!$A$1.

  • name_font

    Set the font properties for the axis title. (Applicable to category and value axes).

        $chart->set_x_axis( name_font => { name => 'Arial', size => 10 } );
  • name_layout

    Set the (x, y) position of the axis caption in chart relative units. (Applicable to category and value axes).

        $chart->set_x_axis(
            name        => 'X axis',
            name_layout => {
                x => 0.34,
                y => 0.85,
            }
        );

    See the "CHART LAYOUT" section below.

  • num_font

    Set the font properties for the axis numbers. (Applicable to category and value axes).

        $chart->set_x_axis( num_font => { bold => 1, italic => 1 } );

    See the "CHART FONTS" section below.

  • num_format

    Set the number format for the axis. (Applicable to category and value axes).

        $chart->set_x_axis( num_format => '#,##0.00' );
        $chart->set_y_axis( num_format => '0.00%'    );

    The number format is similar to the Worksheet Cell Format num_format apart from the fact that a format index cannot be used. The explicit format string must be used as shown above. See "set_num_format()" in Excel::Writer::XLSX for more information.

  • line

    Set the properties of the axis line type such as colour and width. See the "CHART FORMATTING" section below.

        $chart->set_x_axis( line => { none => 1 });
  • fill

    Set the fill properties of the axis such as colour. See the "CHART FORMATTING" section below. Note, in Excel the axis fill is applied to the area of the numbers of the axis and not to the area of the axis bounding box. That background is set from the chartarea fill.

  • min

    Set the minimum value for the axis range. (Applicable to value axes only.)

        $chart->set_x_axis( min => 20 );
  • max

    Set the maximum value for the axis range. (Applicable to value axes only.)

        $chart->set_x_axis( max => 80 );
  • minor_unit

    Set the increment of the minor units in the axis range. (Applicable to value axes only.)

        $chart->set_x_axis( minor_unit => 0.4 );
  • major_unit

    Set the increment of the major units in the axis range. (Applicable to value axes only.)

        $chart->set_x_axis( major_unit => 2 );
  • interval_unit

    Set the interval unit for a category axis. (Applicable to category axes only.)

        $chart->set_x_axis( interval_unit => 2 );
  • crossing

    Set the position where the y axis will cross the x axis. (Applicable to category and value axes.)

    The crossing value can either be the string 'max' to set the crossing at the maximum axis value or a numeric value.

        $chart->set_x_axis( crossing => 3 );
        # or
        $chart->set_x_axis( crossing => 'max' );

    For category axes the numeric value must be an integer to represent the category number that the axis crosses at. For value axes it can have any value associated with the axis.

    If crossing is omitted (the default) the crossing will be set automatically by Excel based on the chart data.

  • position_axis

    Position the axis on or between the axis tick marks. (Applicable to category axes only.)

    There are two allowable values on_tick and between:

        $chart->set_x_axis( position_axis => 'on_tick' );
        $chart->set_x_axis( position_axis => 'between' );
  • reverse

    Reverse the order of the axis categories or values. (Applicable to category and value axes.)

        $chart->set_x_axis( reverse => 1 );
  • log_base

    Set the log base of the axis range. (Applicable to value axes only.)

        $chart->set_x_axis( log_base => 10 );
  • label_position

    Set the "Axis labels" position for the axis. The following positions are available:

        next_to (the default)
        high
        low
        none
  • major_gridlines

    Configure the major gridlines for the axis. The available properties are:

        visible
        line

    For example:

        $chart->set_x_axis(
            major_gridlines => {
                visible => 1,
                line    => { color => 'red', width => 1.25, dash_type => 'dash' }
            }
        );

    The visible property is usually on for the X-axis but it depends on the type of chart.

    The line property sets the gridline properties such as colour and width. See the "CHART FORMATTING" section below.

  • minor_gridlines

    This takes the same options as major_gridlines above.

    The minor gridline visible property is off by default for all chart types.

  • visible

    Configure the visibility of the axis.

        $chart->set_x_axis( visible => 0 );
  • date_axis

    This option is used to treat a category axis with date or time data as a Date Axis. (Applicable to category axes only.)

        $chart->set_x_axis( date_axis => 1 );

    This option also allows you to set max and min values for a category axis which isn't allowed by Excel for non-date category axes.

    See "Date Category Axes" for more details.

  • text_axis

    This option is used to treat a category axis explicitly as a Text Axis. (Applicable to category axes only.)

        $chart->set_x_axis( text_axis => 1 );
  • minor_unit_type

    For date_axis axes, see above, this option is used to set the type of the minor units. (Applicable to date category axes only.)

        $chart->set_x_axis(
            date_axis         => 1,
            minor_unit        => 4,
            minor_unit_type   => 'months',
        );

    The allowable values for this option are days, months and years.

  • major_unit_type

    Same as minor_unit_type, see above, but for major axes unit types.

    More than one property can be set in a call to set_x_axis():

        $chart->set_x_axis(
            name => 'Quarterly results',
            min  => 10,
            max  => 80,
        );
  • display_units

    Set the display units for the axis. This can be useful if the axis numbers are very large but you don't want to represent them in scientific notation. (Applicable to value axes only.) The available display units are:

        hundreds
        thousands
        ten_thousands
        hundred_thousands
        millions
        ten_millions
        hundred_millions
        billions
        trillions

    Example:

        $chart->set_x_axis( display_units => 'thousands' )
        $chart->set_y_axis( display_units => 'millions' )

    * display_units_visible

    Control the visibility of the display units turned on by the previous option. This option is on by default. (Applicable to value axes only.)::

        $chart->set_x_axis( display_units         => 'thousands',
                            display_units_visible => 0 )

set_y_axis()

The set_y_axis() method is used to set properties of the Y axis. The properties that can be set are the same as for set_x_axis, see above.

set_x2_axis()

The set_x2_axis() method is used to set properties of the secondary X axis. The properties that can be set are the same as for set_x_axis, see above. The default properties for this axis are:

    label_position => 'none',
    crossing       => 'max',
    visible        => 0,

set_y2_axis()

The set_y2_axis() method is used to set properties of the secondary Y axis. The properties that can be set are the same as for set_x_axis, see above. The default properties for this axis are:

    major_gridlines => { visible => 0 }

combine()

The chart combine() method is used to combine two charts of different types, for example a column and line chart:

    my $column_chart = $workbook->add_chart( type => 'column', embedded => 1 );

    # Configure the data series for the primary chart.
    $column_chart->add_series(...);

    # Create a new column chart. This will use this as the secondary chart.
    my $line_chart = $workbook->add_chart( type => 'line', embedded => 1 );

    # Configure the data series for the secondary chart.
    $line_chart->add_series(...);

    # Combine the charts.
    $column_chart->combine( $line_chart );

See "Combined Charts" for more details.

set_size()

The set_size() method is used to set the dimensions of the chart. The size properties that can be set are:

     width
     height
     x_scale
     y_scale
     x_offset
     y_offset

The width and height are in pixels. The default chart width is 480 pixels and the default height is 288 pixels. The size of the chart can be modified by setting the width and height or by setting the x_scale and y_scale:

    $chart->set_size( width => 720, height => 576 );

    # Same as:

    $chart->set_size( x_scale => 1.5, y_scale => 2 );

The x_offset and y_offset position the top left corner of the chart in the cell that it is inserted into.

Note: the x_scale, y_scale, x_offset and y_offset parameters can also be set via the insert_chart() method:

    $worksheet->insert_chart( 'E2', $chart, 2, 4, 1.5, 2 );

set_title()

The set_title() method is used to set properties of the chart title.

    $chart->set_title( name => 'Year End Results' );

The properties that can be set are:

  • name

    Set the name (title) for the chart. The name is displayed above the chart. The name can also be a formula such as =Sheet1!$A$1. The name property is optional. The default is to have no chart title.

  • name_font

    Set the font properties for the chart title. See the "CHART FONTS" section below.

  • overlay

    Allow the title to be overlaid on the chart. Generally used with the layout property below.

  • layout

    Set the (x, y) position of the title in chart relative units:

        $chart->set_title(
            name    => 'Title',
            overlay => 1,
            layout  => {
                x => 0.42,
                y => 0.14,
            }
        );

    See the "CHART LAYOUT" section below.

  • none

    By default Excel adds an automatic chart title to charts with a single series and a user defined series name. The none option turns this default title off. It also turns off all other set_title() options.

        $chart->set_title( none => 1 );

set_legend()

The set_legend() method is used to set properties of the chart legend.

The properties that can be set are:

  • none

    The none option turns off the chart legend. In Excel chart legends are on by default:

        $chart->set_legend( none => 1 );

    Note, for backward compatibility, it is also possible to turn off the legend via the position property:

        $chart->set_legend( position => 'none' );
  • position

    Set the position of the chart legend.

        $chart->set_legend( position => 'bottom' );

    The default legend position is right. The available positions are:

        top
        bottom
        left
        right
        overlay_left
        overlay_right
        none
  • layout

    Set the (x, y) position of the legend in chart relative units:

        $chart->set_legend(
            layout => {
                x      => 0.80,
                y      => 0.37,
                width  => 0.12,
                height => 0.25,
            }
        );

    See the "CHART LAYOUT" section below.

  • delete_series

    This allows you to remove 1 or more series from the legend (the series will still display on the chart). This property takes an array ref as an argument and the series are zero indexed:

        # Delete/hide series index 0 and 2 from the legend.
        $chart->set_legend( delete_series => [0, 2] );
  • font

    Set the font properties of the chart legend:

        $chart->set_legend( font => { bold => 1, italic => 1 } );

    See the "CHART FONTS" section below.

set_chartarea()

The set_chartarea() method is used to set the properties of the chart area.

    $chart->set_chartarea(
        border => { none  => 1 },
        fill   => { color => 'red' }
    );

The properties that can be set are:

  • border

    Set the border properties of the chartarea such as colour and style. See the "CHART FORMATTING" section below.

  • fill

    Set the fill properties of the chartarea such as colour. See the "CHART FORMATTING" section below.

set_plotarea()

The set_plotarea() method is used to set properties of the plot area of a chart.

    $chart->set_plotarea(
        border => { color => 'yellow', width => 1, dash_type => 'dash' },
        fill   => { color => '#92D050' }
    );

The properties that can be set are:

  • border

    Set the border properties of the plotarea such as colour and style. See the "CHART FORMATTING" section below.

  • fill

    Set the fill properties of the plotarea such as colour. See the "CHART FORMATTING" section below.

  • layout

    Set the (x, y) position of the plotarea in chart relative units:

        $chart->set_plotarea(
            layout => {
                x      => 0.35,
                y      => 0.26,
                width  => 0.62,
                height => 0.50,
            }
        );

    See the "CHART LAYOUT" section below.

set_style()

The set_style() method is used to set the style of the chart to one of the 42 built-in styles available on the 'Design' tab in Excel:

    $chart->set_style( 4 );

The default style is 2.

set_table()

The set_table() method adds a data table below the horizontal axis with the data used to plot the chart.

    $chart->set_table();

The available options, with default values are:

    vertical   => 1,    # Display vertical lines in the table.
    horizontal => 1,    # Display horizontal lines in the table.
    outline    => 1,    # Display an outline in the table.
    show_keys  => 0     # Show the legend keys with the table data.

The data table can only be shown with Bar, Column, Line, Area and stock charts.

set_up_down_bars

The set_up_down_bars() method adds Up-Down bars to Line charts to indicate the difference between the first and last data series.

    $chart->set_up_down_bars();

It is possible to format the up and down bars to add fill and border properties if required. See the "CHART FORMATTING" section below.

    $chart->set_up_down_bars(
        up   => { fill => { color => 'green' } },
        down => { fill => { color => 'red' } },
    );

Up-down bars can only be applied to Line charts and to Stock charts (by default).

set_drop_lines

The set_drop_lines() method adds Drop Lines to charts to show the Category value of points in the data.

    $chart->set_drop_lines();

It is possible to format the Drop Line line properties if required. See the "CHART FORMATTING" section below.

    $chart->set_drop_lines( line => { color => 'red', dash_type => 'square_dot' } );

Drop Lines are only available in Line, Area and Stock charts.

set_high_low_lines

The set_high_low_lines() method adds High-Low lines to charts to show the maximum and minimum values of points in a Category.

    $chart->set_high_low_lines();

It is possible to format the High-Low Line line properties if required. See the "CHART FORMATTING" section below.

    $chart->set_high_low_lines( line => { color => 'red' } );

High-Low Lines are only available in Line and Stock charts.

show_blanks_as()

The show_blanks_as() method controls how blank data is displayed in a chart.

    $chart->show_blanks_as( 'span' );

The available options are:

        gap    # Blank data is shown as a gap. The default.
        zero   # Blank data is displayed as zero.
        span   # Blank data is connected with a line.

show_hidden_data()

Display data in hidden rows or columns on the chart.

    $chart->show_hidden_data();

SERIES OPTIONS

This section details the following properties of add_series() in more detail:

    marker
    trendline
    y_error_bars
    x_error_bars
    data_labels
    points
    smooth

Marker

The marker format specifies the properties of the markers used to distinguish series on a chart. In general only Line and Scatter chart types and trendlines use markers.

The following properties can be set for marker formats in a chart.

    type
    size
    border
    fill

The type property sets the type of marker that is used with a series.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        marker     => { type => 'diamond' },
    );

The following type properties can be set for marker formats in a chart. These are shown in the same order as in the Excel format dialog.

    automatic
    none
    square
    diamond
    triangle
    x
    star
    short_dash
    long_dash
    circle
    plus

The automatic type is a special case which turns on a marker using the default marker style for the particular series number.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        marker     => { type => 'automatic' },
    );

If automatic is on then other marker properties such as size, border or fill cannot be set.

The size property sets the size of the marker and is generally used in conjunction with type.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        marker     => { type => 'diamond', size => 7 },
    );

Nested border and fill properties can also be set for a marker. See the "CHART FORMATTING" section below.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        marker     => {
            type    => 'square',
            size    => 5,
            border  => { color => 'red' },
            fill    => { color => 'yellow' },
        },
    );

Trendline

A trendline can be added to a chart series to indicate trends in the data such as a moving average or a polynomial fit.

The following properties can be set for trendlines in a chart series.

    type
    order       (for polynomial trends)
    period      (for moving average)
    forward     (for all except moving average)
    backward    (for all except moving average)
    name
    line

The type property sets the type of trendline in the series.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        trendline  => { type => 'linear' },
    );

The available trendline types are:

    exponential
    linear
    log
    moving_average
    polynomial
    power

A polynomial trendline can also specify the order of the polynomial. The default value is 2.

    $chart->add_series(
        values    => '=Sheet1!$B$1:$B$5',
        trendline => {
            type  => 'polynomial',
            order => 3,
        },
    );

A moving_average trendline can also specify the period of the moving average. The default value is 2.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        trendline  => {
            type   => 'moving_average',
            period => 3,
        },
    );

The forward and backward properties set the forecast period of the trendline.

    $chart->add_series(
        values    => '=Sheet1!$B$1:$B$5',
        trendline => {
            type     => 'linear',
            forward  => 0.5,
            backward => 0.5,
        },
    );

The name property sets an optional name for the trendline that will appear in the chart legend. If it isn't specified the Excel default name will be displayed. This is usually a combination of the trendline type and the series name.

    $chart->add_series(
        values    => '=Sheet1!$B$1:$B$5',
        trendline => {
            type => 'linear',
            name => 'Interpolated trend',
        },
    );

Several of these properties can be set in one go:

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        trendline  => {
            type     => 'linear',
            name     => 'My trend name',
            forward  => 0.5,
            backward => 0.5,
            line     => {
                color     => 'red',
                width     => 1,
                dash_type => 'long_dash',
            },
        },
    );

Trendlines cannot be added to series in a stacked chart or pie chart, radar chart, doughnut or (when implemented) to 3D, or surface charts.

Error Bars

Error bars can be added to a chart series to indicate error bounds in the data. The error bars can be vertical y_error_bars (the most common type) or horizontal x_error_bars (for Bar and Scatter charts only).

The following properties can be set for error bars in a chart series.

    type
    value        (for all types except standard error and custom)
    plus_values  (for custom only)
    minus_values (for custom only)
    direction
    end_style
    line

The type property sets the type of error bars in the series.

    $chart->add_series(
        values       => '=Sheet1!$B$1:$B$5',
        y_error_bars => { type => 'standard_error' },
    );

The available error bars types are available:

    fixed
    percentage
    standard_deviation
    standard_error
    custom

All error bar types, except for standard_error and custom must also have a value associated with it for the error bounds:

    $chart->add_series(
        values       => '=Sheet1!$B$1:$B$5',
        y_error_bars => {
            type  => 'percentage',
            value => 5,
        },
    );

The custom error bar type must specify plus_values and minus_values which should either by a Sheet1!$A$1:$A$5 type range formula or an arrayref of values:

    $chart->add_series(
        categories   => '=Sheet1!$A$1:$A$5',
        values       => '=Sheet1!$B$1:$B$5',
        y_error_bars => {
            type         => 'custom',
            plus_values  => '=Sheet1!$C$1:$C$5',
            minus_values => '=Sheet1!$D$1:$D$5',
        },
    );

    # or


    $chart->add_series(
        categories   => '=Sheet1!$A$1:$A$5',
        values       => '=Sheet1!$B$1:$B$5',
        y_error_bars => {
            type         => 'custom',
            plus_values  => [1, 1, 1, 1, 1],
            minus_values => [2, 2, 2, 2, 2],
        },
    );

Note, as in Excel the items in the minus_values do not need to be negative.

The direction property sets the direction of the error bars. It should be one of the following:

    plus    # Positive direction only.
    minus   # Negative direction only.
    both    # Plus and minus directions, The default.

The end_style property sets the style of the error bar end cap. The options are 1 (the default) or 0 (for no end cap):

    $chart->add_series(
        values       => '=Sheet1!$B$1:$B$5',
        y_error_bars => {
            type      => 'fixed',
            value     => 2,
            end_style => 0,
            direction => 'minus'
        },
    );

Data Labels

Data labels can be added to a chart series to indicate the values of the plotted data points.

The following properties can be set for data_labels formats in a chart.

    value
    category
    series_name
    position
    percentage
    leader_lines
    separator
    legend_key
    num_format
    font

The value property turns on the Value data label for a series.

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { value => 1 },
    );

The category property turns on the Category Name data label for a series.

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { category => 1 },
    );

The series_name property turns on the Series Name data label for a series.

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { series_name => 1 },
    );

The position property is used to position the data label for a series.

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { value => 1, position => 'center' },
    );

In Excel the data label positions vary for different chart types. The allowable positions are:

    |  Position     |  Line     |  Bar      |  Pie      |  Area     |
    |               |  Scatter  |  Column   |  Doughnut |  Radar    |
    |               |  Stock    |           |           |           |
    |---------------|-----------|-----------|-----------|-----------|
    |  center       |  Yes      |  Yes      |  Yes      |  Yes*     |
    |  right        |  Yes*     |           |           |           |
    |  left         |  Yes      |           |           |           |
    |  above        |  Yes      |           |           |           |
    |  below        |  Yes      |           |           |           |
    |  inside_base  |           |  Yes      |           |           |
    |  inside_end   |           |  Yes      |  Yes      |           |
    |  outside_end  |           |  Yes*     |  Yes      |           |
    |  best_fit     |           |           |  Yes*     |           |

Note: The * indicates the default position for each chart type in Excel, if a position isn't specified.

The percentage property is used to turn on the display of data labels as a Percentage for a series. It is mainly used for pie and doughnut charts.

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { percentage => 1 },
    );

The leader_lines property is used to turn on Leader Lines for the data label for a series. It is mainly used for pie charts.

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { value => 1, leader_lines => 1 },
    );

Note: Even when leader lines are turned on they aren't automatically visible in Excel or Excel::Writer::XLSX. Due to an Excel limitation (or design) leader lines only appear if the data label is moved manually or if the data labels are very close and need to be adjusted automatically.

The separator property is used to change the separator between multiple data label items:

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { percentage => 1 },
        data_labels => { value => 1, category => 1, separator => "\n" },
    );

The separator value must be one of the following strings:

            ','
            ';'
            '.'
            "\n"
            ' '

The legend_key property is used to turn on Legend Key for the data label for a series:

    $chart->add_series(
        values      => '=Sheet1!$B$1:$B$5',
        data_labels => { value => 1, legend_key => 1 },
    );

The num_format property is used to set the number format for the data labels.

    $chart->add_series(
        values      => '=Sheet1!$A$1:$A$5',
        data_labels => { value => 1, num_format => '#,##0.00' },
    );

The number format is similar to the Worksheet Cell Format num_format apart from the fact that a format index cannot be used. The explicit format string must be used as shown above. See "set_num_format()" in Excel::Writer::XLSX for more information.

The font property is used to set the font properties of the data labels in a series:

    $chart->add_series(
        values      => '=Sheet1!$A$1:$A$5',
        data_labels => {
            value => 1,
            font  => { name => 'Consolas' }
        },
    );

See the "CHART FONTS" section below.

Points

In general formatting is applied to an entire series in a chart. However, it is occasionally required to format individual points in a series. In particular this is required for Pie and Doughnut charts where each segment is represented by a point.

In these cases it is possible to use the points property of add_series():

    $chart->add_series(
        values => '=Sheet1!$A$1:$A$3',
        points => [
            { fill => { color => '#FF0000' } },
            { fill => { color => '#CC0000' } },
            { fill => { color => '#990000' } },
        ],
    );

The points property takes an array ref of format options (see the "CHART FORMATTING" section below). To assign default properties to points in a series pass undef values in the array ref:

    # Format point 3 of 3 only.
    $chart->add_series(
        values => '=Sheet1!$A$1:$A$3',
        points => [
            undef,
            undef,
            { fill => { color => '#990000' } },
        ],
    );

    # Format the first point only.
    $chart->add_series(
        values => '=Sheet1!$A$1:$A$3',
        points => [ { fill => { color => '#FF0000' } } ],
    );

Smooth

The smooth option is used to set the smooth property of a line series. It is only applicable to the Line and Scatter chart types.

    $chart->add_series( values => '=Sheet1!$C$1:$C$5',
                        smooth => 1 );

CHART FORMATTING

The following chart formatting properties can be set for any chart object that they apply to (and that are supported by Excel::Writer::XLSX) such as chart lines, column fill areas, plot area borders, markers, gridlines and other chart elements documented above.

    line
    border
    fill

Chart formatting properties are generally set using hash refs.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => { color => 'blue' },
    );

In some cases the format properties can be nested. For example a marker may contain border and fill sub-properties.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => { color => 'blue' },
        marker     => {
            type    => 'square',
            size    => 5,
            border  => { color => 'red' },
            fill    => { color => 'yellow' },
        },
    );

Line

The line format is used to specify properties of line objects that appear in a chart such as a plotted line on a chart or a border.

The following properties can be set for line formats in a chart.

    none
    color
    width
    dash_type

The none property is uses to turn the line off (it is always on by default except in Scatter charts). This is useful if you wish to plot a series with markers but without a line.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => { none => 1 },
    );

The color property sets the color of the line.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => { color => 'red' },
    );

The available colours are shown in the main Excel::Writer::XLSX documentation. It is also possible to set the colour of a line with a HTML style RGB colour:

    $chart->add_series(
        line       => { color => '#FF0000' },
    );

The width property sets the width of the line. It should be specified in increments of 0.25 of a point as in Excel.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => { width => 3.25 },
    );

The dash_type property sets the dash style of the line.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => { dash_type => 'dash_dot' },
    );

The following dash_type values are available. They are shown in the order that they appear in the Excel dialog.

    solid
    round_dot
    square_dot
    dash
    dash_dot
    long_dash
    long_dash_dot
    long_dash_dot_dot

The default line style is solid.

More than one line property can be specified at a time:

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        line       => {
            color     => 'red',
            width     => 1.25,
            dash_type => 'square_dot',
        },
    );

Border

The border property is a synonym for line.

It can be used as a descriptive substitute for line in chart types such as Bar and Column that have a border and fill style rather than a line style. In general chart objects with a border property will also have a fill property.

Fill

The fill format is used to specify filled areas of chart objects such as the interior of a column or the background of the chart itself.

The following properties can be set for fill formats in a chart.

    none
    color

The none property is used to turn the fill property off (it is generally on by default).

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        fill       => { none => 1 },
    );

The color property sets the colour of the fill area.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        fill       => { color => 'red' },
    );

The available colours are shown in the main Excel::Writer::XLSX documentation. It is also possible to set the colour of a fill with a HTML style RGB colour:

    $chart->add_series(
        fill       => { color => '#FF0000' },
    );

The fill format is generally used in conjunction with a border format which has the same properties as a line format.

    $chart->add_series(
        values     => '=Sheet1!$B$1:$B$5',
        border     => { color => 'red' },
        fill       => { color => 'yellow' },
    );

CHART FONTS

The following font properties can be set for any chart object that they apply to (and that are supported by Excel::Writer::XLSX) such as chart titles, axis labels, axis numbering and data labels. They correspond to the equivalent Worksheet cell Format object properties. See "FORMAT_METHODS" in Excel::Writer::XLSX for more information.

    name
    size
    bold
    italic
    underline
    rotation
    color

The following explains the available font properties:

  • name

    Set the font name:

        $chart->set_x_axis( num_font => { name => 'Arial' } );
  • size

    Set the font size:

        $chart->set_x_axis( num_font => { name => 'Arial', size => 10 } );
  • bold

    Set the font bold property, should be 0 or 1:

        $chart->set_x_axis( num_font => { bold => 1 } );
  • italic

    Set the font italic property, should be 0 or 1:

        $chart->set_x_axis( num_font => { italic => 1 } );
  • underline

    Set the font underline property, should be 0 or 1:

        $chart->set_x_axis( num_font => { underline => 1 } );
  • rotation

    Set the font rotation in the range -90 to 90:

        $chart->set_x_axis( num_font => { rotation => 45 } );

    This is useful for displaying large axis data such as dates in a more compact format.

  • color

    Set the font color property. Can be a color index, a color name or HTML style RGB colour:

        $chart->set_x_axis( num_font => { color => 'red' } );
        $chart->set_y_axis( num_font => { color => '#92D050' } );

Here is an example of Font formatting in a Chart program:

    # Format the chart title.
    $chart->set_title(
        name      => 'Sales Results Chart',
        name_font => {
            name  => 'Calibri',
            color => 'yellow',
        },
    );

    # Format the X-axis.
    $chart->set_x_axis(
        name      => 'Month',
        name_font => {
            name  => 'Arial',
            color => '#92D050'
        },
        num_font => {
            name  => 'Courier New',
            color => '#00B0F0',
        },
    );

    # Format the Y-axis.
    $chart->set_y_axis(
        name      => 'Sales (1000 units)',
        name_font => {
            name      => 'Century',
            underline => 1,
            color     => 'red'
        },
        num_font => {
            bold   => 1,
            italic => 1,
            color  => '#7030A0',
        },
    );

CHART LAYOUT

The position of the chart in the worksheet is controlled by the set_size() method shown above.

It is also possible to change the layout of the following chart sub-objects:

    plotarea
    legend
    title
    x_axis caption
    y_axis caption

Here are some examples:

    $chart->set_plotarea(
        layout => {
            x      => 0.35,
            y      => 0.26,
            width  => 0.62,
            height => 0.50,
        }
    );

    $chart->set_legend(
        layout => {
            x      => 0.80,
            y      => 0.37,
            width  => 0.12,
            height => 0.25,
        }
    );

    $chart->set_title(
        name   => 'Title',
        layout => {
            x => 0.42,
            y => 0.14,
        }
    );

    $chart->set_x_axis(
        name        => 'X axis',
        name_layout => {
            x => 0.34,
            y => 0.85,
        }
    );

Note that it is only possible to change the width and height for the plotarea and legend objects. For the other text based objects the width and height are changed by the font dimensions.

The layout units must be a float in the range 0 < x <= 1 and are expressed as a percentage of the chart dimensions as shown below:

Chart object layout.

From this the layout units are calculated as follows:

    layout:
        width  = w / W
        height = h / H
        x      = a / W
        y      = b / H

These units are slightly cumbersome but are required by Excel so that the chart object positions remain relative to each other if the chart is resized by the user.

Note that for plotarea the origin is the top left corner in the plotarea itself and does not take into account the axes.

WORKSHEET METHODS

In Excel a chartsheet (i.e, a chart that isn't embedded) shares properties with data worksheets such as tab selection, headers, footers, margins, and print properties.

In Excel::Writer::XLSX you can set chartsheet properties using the same methods that are used for Worksheet objects.

The following Worksheet methods are also available through a non-embedded Chart object:

    get_name()
    activate()
    select()
    hide()
    set_first_sheet()
    protect()
    set_zoom()
    set_tab_color()

    set_landscape()
    set_portrait()
    set_paper()
    set_margins()
    set_header()
    set_footer()

See Excel::Writer::XLSX for a detailed explanation of these methods.

EXAMPLE

Here is a complete example that demonstrates some of the available features when creating a chart.

    #!/usr/bin/perl

    use strict;
    use warnings;
    use Excel::Writer::XLSX;

    my $workbook  = Excel::Writer::XLSX->new( 'chart.xlsx' );
    my $worksheet = $workbook->add_worksheet();
    my $bold      = $workbook->add_format( bold => 1 );

    # Add the worksheet data that the charts will refer to.
    my $headings = [ 'Number', 'Batch 1', 'Batch 2' ];
    my $data = [
        [ 2,  3,  4,  5,  6,  7 ],
        [ 10, 40, 50, 20, 10, 50 ],
        [ 30, 60, 70, 50, 40, 30 ],

    ];

    $worksheet->write( 'A1', $headings, $bold );
    $worksheet->write( 'A2', $data );

    # Create a new chart object. In this case an embedded chart.
    my $chart = $workbook->add_chart( type => 'column', embedded => 1 );

    # Configure the first series.
    $chart->add_series(
        name       => '=Sheet1!$B$1',
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$B$2:$B$7',
    );

    # Configure second series. Note alternative use of array ref to define
    # ranges: [ $sheetname, $row_start, $row_end, $col_start, $col_end ].
    $chart->add_series(
        name       => '=Sheet1!$C$1',
        categories => [ 'Sheet1', 1, 6, 0, 0 ],
        values     => [ 'Sheet1', 1, 6, 2, 2 ],
    );

    # Add a chart title and some axis labels.
    $chart->set_title ( name => 'Results of sample analysis' );
    $chart->set_x_axis( name => 'Test number' );
    $chart->set_y_axis( name => 'Sample length (mm)' );

    # Set an Excel chart style. Blue colors with white outline and shadow.
    $chart->set_style( 11 );

    # Insert the chart into the worksheet (with an offset).
    $worksheet->insert_chart( 'D2', $chart, 25, 10 );

    __END__

This will produce a chart that looks like this:

Chart example.

Value and Category Axes

Excel differentiates between a chart axis that is used for series categories and an axis that is used for series values.

In the example above the X axis is the category axis and each of the values is evenly spaced. The Y axis (in this case) is the value axis and points are displayed according to their value.

Since Excel treats the axes differently it also handles their formatting differently and exposes different properties for each.

As such some of Excel::Writer::XLSX axis properties can be set for a value axis, some can be set for a category axis and some properties can be set for both.

For example the min and max properties can only be set for value axes and reverse can be set for both. The type of axis that a property applies to is shown in the set_x_axis() section of the documentation above.

Some charts such as Scatter and Stock have two value axes.

Date Axes are a special type of category axis which are explained below.

Date Category Axes

Date Category Axes are category axes that display time or date information. In Excel::Writer::XLSX Date Category Axes are set using the date_axis option:

    $chart->set_x_axis( date_axis => 1 );

In general you should also specify a number format for a date axis although Excel will usually default to the same format as the data being plotted:

    $chart->set_x_axis(
        date_axis         => 1,
        num_format        => 'dd/mm/yyyy',
    );

Excel doesn't normally allow minimum and maximum values to be set for category axes. However, date axes are an exception. The min and max values should be set as Excel times or dates:

    $chart->set_x_axis(
        date_axis         => 1,
        min               => $worksheet->convert_date_time('2013-01-02T'),
        max               => $worksheet->convert_date_time('2013-01-09T'),
        num_format        => 'dd/mm/yyyy',
    );

For date axes it is also possible to set the type of the major and minor units:

    $chart->set_x_axis(
        date_axis         => 1,
        minor_unit        => 4,
        minor_unit_type   => 'months',
        major_unit        => 1,
        major_unit_type   => 'years',
        num_format        => 'dd/mm/yyyy',
    );

Secondary Axes

It is possible to add a secondary axis of the same type to a chart by setting the y2_axis or x2_axis property of the series:

    #!/usr/bin/perl

    use strict;
    use warnings;
    use Excel::Writer::XLSX;

    my $workbook  = Excel::Writer::XLSX->new( 'chart_secondary_axis.xlsx' );
    my $worksheet = $workbook->add_worksheet();

    # Add the worksheet data that the charts will refer to.
    my $data = [
        [ 2,  3,  4,  5,  6,  7 ],
        [ 10, 40, 50, 20, 10, 50 ],

    ];

    $worksheet->write( 'A1', $data );

    # Create a new chart object. In this case an embedded chart.
    my $chart = $workbook->add_chart( type => 'line', embedded => 1 );

    # Configure a series with a secondary axis
    $chart->add_series(
        values  => '=Sheet1!$A$1:$A$6',
        y2_axis => 1,
    );

    $chart->add_series(
        values => '=Sheet1!$B$1:$B$6',
    );


    # Insert the chart into the worksheet.
    $worksheet->insert_chart( 'D2', $chart );

    __END__

It is also possible to have a secondary, combined, chart either with a shared or secondary axis, see below.

Combined Charts

It is also possible to combine two different chart types, for example a column and line chart to create a Pareto chart using the Chart combine() method:

Chart image.

Here is a simpler example:

    use strict;
    use warnings;
    use Excel::Writer::XLSX;

    my $workbook  = Excel::Writer::XLSX->new( 'chart_combined.xlsx' );
    my $worksheet = $workbook->add_worksheet();
    my $bold      = $workbook->add_format( bold => 1 );

    # Add the worksheet data that the charts will refer to.
    my $headings = [ 'Number', 'Batch 1', 'Batch 2' ];
    my $data = [
        [ 2,  3,  4,  5,  6,  7 ],
        [ 10, 40, 50, 20, 10, 50 ],
        [ 30, 60, 70, 50, 40, 30 ],

    ];

    $worksheet->write( 'A1', $headings, $bold );
    $worksheet->write( 'A2', $data );

    #
    # In the first example we will create a combined column and line chart.
    # They will share the same X and Y axes.
    #

    # Create a new column chart. This will use this as the primary chart.
    my $column_chart = $workbook->add_chart( type => 'column', embedded => 1 );

    # Configure the data series for the primary chart.
    $column_chart->add_series(
        name       => '=Sheet1!$B$1',
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$B$2:$B$7',
    );

    # Create a new column chart. This will use this as the secondary chart.
    my $line_chart = $workbook->add_chart( type => 'line', embedded => 1 );

    # Configure the data series for the secondary chart.
    $line_chart->add_series(
        name       => '=Sheet1!$C$1',
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$C$2:$C$7',
    );

    # Combine the charts.
    $column_chart->combine( $line_chart );

    # Add a chart title and some axis labels. Note, this is done via the
    # primary chart.
    $column_chart->set_title( name => 'Combined chart - same Y axis' );
    $column_chart->set_x_axis( name => 'Test number' );
    $column_chart->set_y_axis( name => 'Sample length (mm)' );


    # Insert the chart into the worksheet
    $worksheet->insert_chart( 'E2', $column_chart );

Chart image.

The secondary chart can also be placed on a secondary axis using the methods shown in the previous section.

In this case it is just necessary to add a y2_axis parameter to the series and, if required, add a title using set_y2_axis(). The following are the additions to the previous example to place the secondary chart on the secondary axis:

    ...

    $line_chart->add_series(
        name       => '=Sheet1!$C$1',
        categories => '=Sheet1!$A$2:$A$7',
        values     => '=Sheet1!$C$2:$C$7',
        y2_axis    => 1,
    );

    ...

    $column_chart->set_y2_axis( name => 'Target length (mm)' );

Chart image.

The examples above use the concept of a primary and secondary chart. The primary chart is the chart that defines the primary X and Y axis. It is also used for setting all chart properties apart from the secondary data series. For example the chart title and axes properties should be set via the primary chart.

See also chart_combined.pl and chart_pareto.pl examples in the distro for more detailed examples.

There are some limitations on combined charts:

  • Pie charts cannot currently be combined.

  • Scatter charts cannot currently be used as a primary chart but they can be used as a secondary chart.

  • Bar charts can only combined secondary charts on a secondary axis. This is an Excel limitation.

TODO

Chart features that are on the TODO list and will hopefully be added are:

  • Add more chart sub-types.

  • Additional formatting options.

  • More axis controls.

  • 3D charts.

  • Additional chart types.

If you are interested in sponsoring a feature to have it implemented or expedited let me know.

AUTHOR

John McNamara jmcnamara@cpan.org

COPYRIGHT

Copyright MM-MMXV, John McNamara.

All Rights Reserved. This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.