/* origin: FreeBSD /usr/src/lib/msun/src/s_atan.c * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ /* atan(x) * Method * 1. Reduce x to positive by atan(x) = -atan(-x). * 2. According to the integer k=4t+0.25 chopped, t=x, the argument * is further reduced to one of the following intervals and the * arctangent of t is evaluated by the corresponding formula: * * [0,7/16] atan(x) = t-t^3*(a1+t^2*(a2+...(a10+t^2*a11)...) * [7/16,11/16] atan(x) = atan(1/2) + atan( (t-0.5)/(1+t/2) ) * [11/16.19/16] atan(x) = atan( 1 ) + atan( (t-1)/(1+t) ) * [19/16,39/16] atan(x) = atan(3/2) + atan( (t-1.5)/(1+1.5t) ) * [39/16,INF] atan(x) = atan(INF) + atan( -1/t ) * * Constants: * The hexadecimal values are the intended ones for the following * constants. The decimal values may be used, provided that the * compiler will convert from decimal to binary accurately enough * to produce the hexadecimal values shown. */ /* origin: FreeBSD /usr/src/lib/msun/src/s_atanf.c */ /* * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ module std::math;