catan Function (ROM Call 0x13C)

math.h, timath.h

void catan (float z_re, float z_im, float *w_re, float *w_im);

Complex arc tangent.

catan calculates the arc tangent w = atan(z) of the complex number which real and imaginary parts are z_re and z_im, and stores real and imaginary part of the result in floating point destinations pointed to by w_re and w_im. The complex arc tangent is defined by

atan(z) = -i ln ((1 + i z) / (1 - i z)) / 2

where ln is complex natural logarithm (see cln).


Uses: atan2, atanh, fabs, pow, _bcd_math
Used by: catanh