Make sin wave with GD

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi. I using GD package to make wave. But it does not work.

use GD::Simple;
$i = GD::Simple->new(400,400);
($x1,$y1) = (0,0);
for ($x2=0; $x2<=400; $x2+=10) {
    $y2 = sin($x2)*400;
    $i->moveTo($x1,$y1);
    $i->lineTo($x2,$y2);
    ($x1,$y1) = ($x2,$y2);
}
print $i->png;

How do I get right value for y2? Thank.

Comment on Make sin wave with GD

Replies are listed 'Best First'.
Re: Make sin wave with GD by pme (Monsignor) on Jul 01, 2015 at 17:05 UTC
sin() takes argument in the form of radian.	[reply]
Re^2: Make sin wave with GD by Anonymous Monk on Jul 01, 2015 at 17:12 UTC
Ok. Thank you. I convert to radians but now wave is upsidedown and clipped.	[reply]
Re^3: Make sin wave with GD by pme (Monsignor) on Jul 01, 2015 at 17:25 UTC
The 0,0 point is the upper left corner of your 400x400 GD plane if i am not mistaken.	[reply]
Re^4: Make sin wave with GD by Anonymous Monk on Jul 01, 2015 at 17:40 UTC
Re^5: Make sin wave with GD by sn1987a (Curate) on Jul 01, 2015 at 18:14 UTC
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