cvFastArctan     1210 modules/core/include/opencv2/core/core_c.h CVAPI(float) cvFastArctan( float y, float x );
cvFastArctan      288 modules/imgproc/src/hough.cpp                 t = (float) fabs( cvFastArctan( yc, xc ) * d2r );
cvFastArctan      356 modules/imgproc/src/hough.cpp                     t = (float) fabs( cvFastArctan( yc, xc ) * d2r );