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authorSandeep Gupta2017-06-18 23:55:40 +0530
committerSandeep Gupta2017-06-18 23:55:40 +0530
commit277d1edfa17bf3719d90ddbac8e31f6181e952c3 (patch)
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+/*
+ * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
+ * Copyright (C) 2008-2008 - INRIA - Bruno JOFRET
+ * Copyright (C) Bruno Pincon
+
+ *
+ * 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 "log1p.h"
+#include "log.h"
+#include "lnp1m1.h"
+
+float slog1ps(float in) {
+ static double A = -1.0/3.0;
+ static double B = 0.5;
+
+ if(in < -1)
+ {/* got NaN */
+ return (in - in) / (in - in); /* NaN */
+ }
+ else if(A <= in && in <= B)
+ {/* use the function log((1+g)/(1-g)) with g = x/(x + 2) */
+ return slnp1m1s(in / (in + 2));
+ }
+ else
+ {/* use the standard formula */
+ return slogs(in + 1);
+ }
+}