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/* |
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* ==================================================== |
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
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* |
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* Developed at SunPro, a Sun Microsystems, Inc. business. |
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* Permission to use, copy, modify, and distribute this |
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* software is freely granted, provided that this notice |
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* is preserved. |
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* ==================================================== |
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*/ |
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FUNCTION |
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<>, <>---base 10 logarithms |
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log10 |
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INDEX |
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log10f |
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#include |
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double log10(double <[x]>); |
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float log10f(float <[x]>); |
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#include |
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double log10(<[x]>) |
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double <[x]>; |
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float <[x]>; |
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<> returns the base 10 logarithm of <[x]>. |
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It is implemented as <) / log(10)>>. |
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<> and <> return the calculated value. |
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<> is ANSI C. <> is an extension. |
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* wrapper log10(X) |
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*/ |
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#include |
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double log10(double x) /* wrapper log10 */ |
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#else |
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double log10(x) /* wrapper log10 */ |
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double x; |
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#endif |
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{ |
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#ifdef _IEEE_LIBM |
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return __ieee754_log10(x); |
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#else |
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double z; |
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struct exception exc; |
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z = __ieee754_log10(x); |
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if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; |
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if(x<=0.0) { |
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#ifndef HUGE_VAL |
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#define HUGE_VAL inf |
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double inf = 0.0; |
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#endif |
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exc.name = "log10"; |
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exc.err = 0; |
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exc.arg1 = x; |
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exc.arg2 = x; |
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if (_LIB_VERSION == _SVID_) |
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exc.retval = -HUGE; |
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else |
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exc.retval = -HUGE_VAL; |
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if(x==0.0) { |
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/* log10(0) */ |
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exc.type = SING; |
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if (_LIB_VERSION == _POSIX_) |
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errno = ERANGE; |
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else if (!matherr(&exc)) { |
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errno = ERANGE; |
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} |
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} else { |
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/* log10(x<0) */ |
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exc.type = DOMAIN; |
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if (_LIB_VERSION == _POSIX_) |
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errno = EDOM; |
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else if (!matherr(&exc)) { |
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errno = EDOM; |
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} |
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exc.retval = nan(""); |
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} |
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if (exc.err != 0) |
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errno = exc.err; |
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return exc.retval; |
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} else |
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return z; |
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#endif |
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} |
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