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| author | Siddhesh Wani | 2015-05-25 14:46:31 +0530 |
|---|---|---|
| committer | Siddhesh Wani | 2015-05-25 14:46:31 +0530 |
| commit | db464f35f5a10b58d9ed1085e0b462689adee583 (patch) | |
| tree | de5cdbc71a54765d9fec33414630ae2c8904c9b8 /src/c/elementaryFunctions/log1p/slog1ps.c | |
| download | scilab2c-db464f35f5a10b58d9ed1085e0b462689adee583.tar.gz scilab2c-db464f35f5a10b58d9ed1085e0b462689adee583.tar.bz2 scilab2c-db464f35f5a10b58d9ed1085e0b462689adee583.zip | |
Original Version
Diffstat (limited to 'src/c/elementaryFunctions/log1p/slog1ps.c')
| -rw-r--r-- | src/c/elementaryFunctions/log1p/slog1ps.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/c/elementaryFunctions/log1p/slog1ps.c b/src/c/elementaryFunctions/log1p/slog1ps.c new file mode 100644 index 00000000..04786524 --- /dev/null +++ b/src/c/elementaryFunctions/log1p/slog1ps.c @@ -0,0 +1,35 @@ +/*
+ * 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);
+ }
+}
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