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author | jofret | 2009-04-28 06:53:00 +0000 |
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committer | jofret | 2009-04-28 06:53:00 +0000 |
commit | b56c1d5508edf80f36c9a48e8806641f5cdf2cd8 (patch) | |
tree | 921ff5c8b47befe9b797cffa57bea9c940a7224c /src/c/elementaryFunctions/log/clogs.c | |
parent | 127ac18608c72acfed9d59599252ad62cb562ee5 (diff) | |
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Moving source code
Diffstat (limited to 'src/c/elementaryFunctions/log/clogs.c')
-rw-r--r-- | src/c/elementaryFunctions/log/clogs.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/c/elementaryFunctions/log/clogs.c b/src/c/elementaryFunctions/log/clogs.c new file mode 100644 index 00000000..d402d1d1 --- /dev/null +++ b/src/c/elementaryFunctions/log/clogs.c @@ -0,0 +1,64 @@ +/* + * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab + * Copyright (C) 2007-2008 - INRIA - Bruno JOFRET + * + * This file must be used under the terms of the CeCILL. + * This source file is licensed as described in the file COPYING, which + * you should have received as part of this distribution. The terms + * are also available at + * http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt + * + */ + +#include <math.h> +#include "log.h" +#include "lapack.h" +#include "log1p.h" +#include "pythag.h" + +floatComplex clogs(floatComplex in) { + static float sR2 = 1.41421356237309504f; + + float _RealIn = creals(in); + float _ImgIn = cimags(in); + + float _RealOut = 0; + float _ImgOut = 0; + + float RMax = (float) getOverflowThreshold(); + float LInf = sqrtf((float) getUnderflowThreshold()); + float LSup = sqrtf(0.5f * RMax); + + float AbsReal = fabsf(_RealIn); + float AbsImg = fabsf(_ImgIn); + + _ImgOut = atan2f(_ImgIn, _RealIn); + + if(_ImgIn > _RealIn) + {/* switch Real part and Imaginary part */ + float Temp = AbsReal; + AbsReal = AbsImg; + AbsImg = Temp; + } + + if((0.5 <= AbsReal) && (AbsReal <= sR2)) + _RealOut = 0.5f * slog1ps((AbsReal - 1.0f) * (AbsReal + 1.0f) + AbsImg * AbsImg); + else if(LInf < AbsImg && AbsReal < LSup) + _RealOut = 0.5f * slogs(AbsReal * AbsReal + AbsImg * AbsImg); + else if(AbsReal > RMax) + _RealOut = AbsReal; + else + { + float Temp = spythags(AbsReal, AbsImg); + if(Temp <= RMax) + { + _RealOut = slogs(Temp); + } + else /* handle rare spurious overflow with : */ + { + float Temp2 = AbsImg/AbsReal; + _RealOut = slogs(AbsReal) + 0.5f * slog1ps(Temp2 * Temp2); + } + } + return FloatComplex(_RealOut, _ImgOut); +} |