NAME
Math::Approx
METHODS
new (constructor)
Math::Approx->new(\&poly, $degree, %data);
If the first argument to the constructor is a CODE reference, this is
used as the function to iterate over the data. Such a function must take
two arguments: The *degree* and the *x* value.
For interpolation with plain polynomials *poly* can be defined as:
sub poly {
my($n,$x) = @_;
return $x ** $n;
}
If the first argument in the constructor is a FALSE value instead of a
CODE reference, then the above plain polynomial *poly* is used as the
iterator function.
The second argument is the maximum degree which should be used for
interpolation. Degrees start with 0.
The rest of the arguments are treated as pairs of x and y samples which
should be approximated.
The constructor returns a Math::Approx reference.
approx
$approximation->approx(17);
The method returns the approximated y value for the x value given as
argument.
fit
$approximation->fit;
Returns the medim square error for the data points.
plot
$approximation->plot("tmp/app");
Prints all data pairs and the corresponding approximation pairs into the
filename given as argument. The output is suitable for usage with
gnuplot(1).
print
$approximation->print;
Prints information about the approximation on *STDOUT*
EXAMPLE
use Math::Approx;
sub poly {
my($n,$x) = @_;
return $x ** $n;
}
for (1..20) {
$x{$_} = sin($_/10)*cos($_/30)+0.3*rand;
}
$a = new Math::Approx (\&poly, 5, %x);
$a->print;
$a->plot("math-approx-demo.out");
print "Fit: ", $a->fit, "\n";
SEE ALSO
gnuplot(1).
AUTHOR
Ulrich Pfeifer