/* sindg.c * * Circular sine of angle in degrees * * * * SYNOPSIS: * * double x, y, sindg(); * * y = sindg( x ); * * * * DESCRIPTION: * * Range reduction is into intervals of 45 degrees. * * Two polynomial approximating functions are employed. * Between 0 and pi/4 the sine is approximated by * x + x**3 P(x**2). * Between pi/4 and pi/2 the cosine is represented as * 1 - x**2 P(x**2). * * * * ACCURACY: * * Relative error: * arithmetic domain # trials peak rms * DEC +-1000 3100 3.3e-17 9.0e-18 * IEEE +-1000 30000 2.3e-16 5.6e-17 * * ERROR MESSAGES: * * message condition value returned * sindg total loss x > 8.0e14 (DEC) 0.0 * x > 1.0e14 (IEEE) * */ /* cosdg.c * * Circular cosine of angle in degrees * * * * SYNOPSIS: * * double x, y, cosdg(); * * y = cosdg( x ); * * * * DESCRIPTION: * * Range reduction is into intervals of 45 degrees. * * Two polynomial approximating functions are employed. * Between 0 and pi/4 the cosine is approximated by * 1 - x**2 P(x**2). * Between pi/4 and pi/2 the sine is represented as * x + x**3 P(x**2). * * * ACCURACY: * * Relative error: * arithmetic domain # trials peak rms * DEC +-1000 3400 3.5e-17 9.1e-18 * IEEE +-1000 30000 2.1e-16 5.7e-17 * See also sin(). * */ /* Cephes Math Library Release 2.0: April, 1987 * Copyright 1985, 1987 by Stephen L. Moshier * Direct inquiries to 30 Frost Street, Cambridge, MA 02140 */ #include "mconf.h" #ifdef UNK static double sincof[] = { 1.58962301572218447952E-10, -2.50507477628503540135E-8, 2.75573136213856773549E-6, -1.98412698295895384658E-4, 8.33333333332211858862E-3, -1.66666666666666307295E-1 }; static double coscof[] = { 1.13678171382044553091E-11, -2.08758833757683644217E-9, 2.75573155429816611547E-7, -2.48015872936186303776E-5, 1.38888888888806666760E-3, -4.16666666666666348141E-2, 4.99999999999999999798E-1 }; static double PI180 = 1.74532925199432957692E-2; /* pi/180 */ static double lossth = 1.0e14; #endif #ifdef DEC static unsigned short sincof[] = { 0030056,0143750,0177170,0073013, 0131727,0027455,0044510,0132205, 0033470,0167432,0131752,0042263, 0135120,0006400,0146776,0174027, 0036410,0104210,0104207,0137202, 0137452,0125252,0125252,0125103 }; static unsigned short coscof[] = { 0027107,0176030,0153315,0110312, 0131017,0072476,0007450,0123243, 0032623,0171174,0070066,0146445, 0134320,0006400,0147355,0163313, 0035666,0005540,0133012,0165067, 0137052,0125252,0125252,0125206, 0040000,0000000,0000000,0000000 }; static unsigned short P1[] = {0036616,0175065,0011224,0164711}; #define PI180 *(double *)P1 static double lossth = 8.0e14; #endif #ifdef IBMPC static unsigned short sincof[] = { 0x0ec1,0x1fcf,0xd8fd,0x3de5, 0x1691,0xa929,0xe5e5,0xbe5a, 0x4896,0x567d,0x1de3,0x3ec7, 0xdf03,0x19bf,0x01a0,0xbf2a, 0xf7d0,0x1110,0x1111,0x3f81, 0x5548,0x5555,0x5555,0xbfc5 }; static unsigned short coscof[] = { 0xb219,0x1ad9,0xff83,0x3da8, 0x14d4,0xc1e5,0xeea7,0xbe21, 0xd9a5,0x8e06,0x7e4f,0x3e92, 0xbcd9,0x19dd,0x01a0,0xbefa, 0x5d47,0x16c1,0xc16c,0x3f56, 0x5551,0x5555,0x5555,0xbfa5, 0x0000,0x0000,0x0000,0x3fe0 }; static unsigned short P1[] = {0x9d39,0xa252,0xdf46,0x3f91}; #define PI180 *(double *)P1 static double lossth = 1.0e14; #endif #ifdef MIEEE static unsigned short sincof[] = { 0x3de5,0xd8fd,0x1fcf,0x0ec1, 0xbe5a,0xe5e5,0xa929,0x1691, 0x3ec7,0x1de3,0x567d,0x4896, 0xbf2a,0x01a0,0x19bf,0xdf03, 0x3f81,0x1111,0x1110,0xf7d0, 0xbfc5,0x5555,0x5555,0x5548 }; static unsigned short coscof[] = { 0x3da8,0xff83,0x1ad9,0xb219, 0xbe21,0xeea7,0xc1e5,0x14d4, 0x3e92,0x7e4f,0x8e06,0xd9a5, 0xbefa,0x01a0,0x19dd,0xbcd9, 0x3f56,0xc16c,0x16c1,0x5d47, 0xbfa5,0x5555,0x5555,0x5551, 0x3fe0,0x0000,0x0000,0x0000 }; static unsigned short P1[] = { 0x3f91,0xdf46,0xa252,0x9d39 }; #define PI180 *(double *)P1 static double lossth = 1.0e14; #endif #ifdef ANSIPROT extern double polevl ( double, void *, int ); extern double floor ( double ); extern double ldexp ( double, int ); #else double polevl(), floor(), ldexp(); #endif extern double PIO4; double sindg(x) double x; { double y, z, zz; int j, sign; /* make argument positive but save the sign */ sign = 1; if( x < 0 ) { x = -x; sign = -1; } if( x > lossth ) { mtherr( "sindg", TLOSS ); return(0.0); } y = floor( x/45.0 ); /* integer part of x/PIO4 */ /* strip high bits of integer part to prevent integer overflow */ z = ldexp( y, -4 ); z = floor(z); /* integer part of y/8 */ z = y - ldexp( z, 4 ); /* y - 16 * (y/16) */ j = z; /* convert to integer for tests on the phase angle */ /* map zeros to origin */ if( j & 1 ) { j += 1; y += 1.0; } j = j & 07; /* octant modulo 360 degrees */ /* reflect in x axis */ if( j > 3) { sign = -sign; j -= 4; } z = x - y * 45.0; /* x mod 45 degrees */ z *= PI180; /* multiply by pi/180 to convert to radians */ zz = z * z; if( (j==1) || (j==2) ) { y = 1.0 - zz * polevl( zz, coscof, 6 ); } else { y = z + z * (zz * polevl( zz, sincof, 5 )); } if(sign < 0) y = -y; return(y); } double cosdg(x) double x; { double y, z, zz; int j, sign; /* make argument positive */ sign = 1; if( x < 0 ) x = -x; if( x > lossth ) { mtherr( "cosdg", TLOSS ); return(0.0); } y = floor( x/45.0 ); z = ldexp( y, -4 ); z = floor(z); /* integer part of y/8 */ z = y - ldexp( z, 4 ); /* y - 16 * (y/16) */ /* integer and fractional part modulo one octant */ j = z; if( j & 1 ) /* map zeros to origin */ { j += 1; y += 1.0; } j = j & 07; if( j > 3) { j -=4; sign = -sign; } if( j > 1 ) sign = -sign; z = x - y * 45.0; /* x mod 45 degrees */ z *= PI180; /* multiply by pi/180 to convert to radians */ zz = z * z; if( (j==1) || (j==2) ) { y = z + z * (zz * polevl( zz, sincof, 5 )); } else { y = 1.0 - zz * polevl( zz, coscof, 6 ); } if(sign < 0) y = -y; return(y); }