Dear group, I cannot figure out why the calculations inside [expr (x*cos(theta))-(y*sin(theta));(x*sin(theta))+(y*cos(theta))] gives me wrong results. The above mentioned formula for rotation is correct. I initialize the values through [value] object before preforming computation. The initial values are: x=1, y=0, theta=1/2pi. I expect the new x and new y to be (0,1) respectively after the rotation. But, for some reason, I get (-1,1). I checked the help files for [value] and [expr] and it looks like I am doing everything right. Anyone have an idea where's the mistake?Thank you!Hrvoje Radnic https://www.instagram.com/singlecycled/
https://pdvrecords.bandcamp.com/album/umovi-protiv-valova https://soundcloud.com/sumovi-protiv-valova 00385(0)915225162
Are you by any chance updating x before running the y calculation? If you do that, y will be calculated using the updated x and not the correct (original) one.
cheers Miller
On 11/29/25 6:49 AM, Hrvoje Radnic via Pd-list wrote:
Dear group,
I cannot figure out why the calculations inside [expr (x*cos(theta))-(y*sin(theta)); (x*sin(theta))+(y*cos(theta))] gives me wrong results.
The above mentioned formula for rotation is correct. I initialize the values through [value] object before preforming computation. The initial values are: x=1, y=0, theta=1/2pi. I expect the new x and new y to be (0,1) respectively after the rotation. But, for some reason, I get (-1,1). I checked the help files for [value] and [expr] and it looks like I am doing everything right. Anyone have an idea where's the mistake? Thank you! Hrvoje Radnic
https://www.instagram.com/singlecycled/ https://urldefense.com/v3/__https://www.instagram.com/singlecycled/__;!!Mih3wA!DfrXKhsjBltnmdIUutLHu6UcsuMDJK4Q2d1t_PgsPezZ7FFjjwd46jjfXesqm2Rx6ggHKPDjhNcNbhmE$
https://pdvrecords.bandcamp.com/album/umovi-protiv-valova https://urldefense.com/v3/__https://pdvrecords.bandcamp.com/album/umovi-protiv-valova__;!!Mih3wA!DfrXKhsjBltnmdIUutLHu6UcsuMDJK4Q2d1t_PgsPezZ7FFjjwd46jjfXesqm2Rx6ggHKPDjhEqqX9g8$ https://soundcloud.com/sumovi-protiv-valova https://urldefense.com/v3/__https://soundcloud.com/sumovi-protiv-valova__;!!Mih3wA!DfrXKhsjBltnmdIUutLHu6UcsuMDJK4Q2d1t_PgsPezZ7FFjjwd46jjfXesqm2Rx6ggHKPDjhLRt9iry$ 00385(0)915225162
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