use PDL::LiteF;
BEGIN {
eval " use PDL::Fit::Linfit; ";
$loaded = ($@ ? 0 : 1);
}
kill INT,$$ if $ENV{UNDER_DEBUGGER}; # Useful for debugging.
print "1..2\n";
unless ($loaded) {
for (1..2) {
print "ok $_ # Skipped: probably PDL::Slatec not available.\n";
}
exit;
}
my $testNo = 1;
# Simple Test Case:
# Generate data from a set of functions
my $xvalues = sequence(100);
$data = 3*$xvalues + 2*cos($xvalues) + 3*sin($xvalues*2);
# Fit functions are the linear, cos, and sin2x functions used in
# the data generation step above:
$fitFuncs = cat $xvalues, cos($xvalues), sin($xvalues*2);
# Perform the fit, Coefs should equal 3,2,3
my ($yfit, $coeffs) = PDL::linfit1d($data,$fitFuncs);
my @coefs = $coeffs->list;
ok( $testNo++, tapprox( $coefs[0], 3) && tapprox( $coefs[1], 2) && tapprox( $coefs[2], 3) );
# More Complex Example
my $noPoints = 501;
my @expectedCoefs = qw( 0.988375918186647 -0.000278823311771375 0.161669997297754 0.0626069008452451);
my $noCoefs = 4;
my $i;
my ($deltaT,$Amp,$lin,$HOper,$AmpHO,$Amphalf,$Ampfull);
my @PulsedB;
my @Pulse;
my $psum = 0;
my $pi = 3.1415926;
my $Pwidth = 2000;
my $pave;
$deltaT = 4; # 4 nS increments
$Amp = 2.8; # 2.8V amplitude of pulse
$lin = .2;
$HOper = 200; # HO period
$AmpHO=.1;
$Amphalf = .5;
$Ampfull = .2;
# generate waveform:
for($i=0;$i<$noPoints;$i++){
$PulsedB[$i]=
-$lin*1e-3*$i*$deltaT +
$Amphalf*sin($pi/$Pwidth*$i*$deltaT) +
$Ampfull*sin(2*$pi/$Pwidth*$i*$deltaT) +
$AmpHO*sin(2*$pi/$HOper*$i*$deltaT);
$Pulse[$i] = $Amp*exp($PulsedB[$i]/20*2.3025851);
$psum += $Pulse[$i]; # used to get DC value
# printf(" %4d %g %g\n",$i,$PulsedB[$i],$Pulse[$i]);
}
$pave = $psum/$noPoints;
# printf("DC Value = %g\n",$pave);
# Make PDL from waveform:
my $data = new PDL( \@Pulse);
# setup matrix contains functions to fit
for ($i=0; $i<$noPoints; $i++) {
$functions[0][$i] = $pave;
$functions[1][$i] = $i;
$functions[2][$i] = sin($pi*$i/($noPoints-1));
$functions[3][$i] = sin(2*$pi*$i/($noPoints-1));
}
my $fitFuncs = new PDL( \@functions);
($yfit, $coeffs) = linfit1d( $data, $fitFuncs);
@coefs = $coeffs->list;
ok( $testNo++, tapprox( $coefs[0], $expectedCoefs[0]) &&
tapprox( $coefs[1], $expectedCoefs[1]) &&
tapprox( $coefs[2], $expectedCoefs[2]) &&
tapprox( $coefs[3], $expectedCoefs[3])
);
sub tapprox {
my($a,$b) = @_;
my $c = abs($a-$b);
my $d = ref($c) ? $c->{PDL}->max : $c ; # don't do a make if were are dealing
# with a scalar
$d < 0.00001;
}
# Testing utility functions:
sub ok {
my $no = shift ;
my $result = shift ;
print "not " unless $result ;
print "ok $no\n" ;
}