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-rw-r--r--2.3-1/src/c/elementaryFunctions/cosh/i8coshs.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/2.3-1/src/c/elementaryFunctions/cosh/i8coshs.c b/2.3-1/src/c/elementaryFunctions/cosh/i8coshs.c
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+/*
+ * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
+ * Copyright (C) 2008-2008 - 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
+ *
+ */
+
+/*
+// cosh(z) = 0.5 (exp(|z|) + exp(-|z|))
+// = 0.5 ( y + 1/y ) with y = exp(|z|)
+*/
+
+#include <math.h>
+#include "cosh.h"
+#include "exp.h"
+#include "abs.h"
+#include "types.h"
+
+float i8coshs(int8 x) {
+ double y = i8exps(i8abss(x));
+ return (0.5 * (y + 1.0/y));
+}