posted 05 May 2014 09:05            

cart2pol2cart.kym

based on ssc´s cartesian to polar patch i just try to convert from polar back to cartesian coordinates using the formulae:
x = mag * cos(phi)
y = mag * sin(phi)
but it doesnt seem to work. the x and y values before and after the convertion (cart to pol to cart) doesn´t match.
did i miss something?

i also wonder how to calculate that (e.g. cos or sin of an angle) in the freq. domain.
this has to be done at samplerate so i cant use capytalk for that, right?

thanks, johannes

posted 05 May 2014 14:06            

* In the reconvert Sounds, change cos to normCos and sin to normSin

* In the Angle SoundToGlobalController, get rid of "1 -" and keep just the pasted in ArcTan Sound.

The ArcTan Sound outputs a "normalized" angle in the range of -1 to +1:

arcTan ( right / left ) / π

so, if you want to convert the "normalized" angle back to X and Y coordinates, you would need to use:

cos ( π * angle ) and sin ( π * angle )

posted 05 May 2014 15:02            

what exactly does "n" in your two equations stands for?
and how can i calculate the latter equation in the the frequency domain at samplerate?

posted 05 May 2014 18:32            

The font makes it look like the letter "n"

To take the sine and cosine at the sample rate, you can use a Waveshaper whose shapingFunction is either the Sine or the Cosine wavetable.

posted 06 May 2014 03:00            

cart2pol2cart_v2.kym

but it seems to that the sine calculated by the waveshaper is 180 degree out of phase to the sine calculated by capytalk, while this doesnt seem to occur for cos. to correct the phase i now multiply the sine function by -1 ...

after some experimentation i also realized some range-limitation of the reconverted x and y values. when setting x and y to 1 or -1 the reconverted x and y will be 0.7 or -0.7 (instead of 1 and -1)

i append two sounds for demonstration…

any help is welcome. ciao, j