nuttx/libs/libc/math/lib_asinh.c
Alin Jerpelea a9bfe50fe1 author: Brennan Ashton: update licenses to Apache
Brennan Ashton has submitted the ICLA
as a result we can migrate the licenses to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-09-02 21:56:05 +08:00

54 lines
1.7 KiB
C

/****************************************************************************
* libs/libc/math/lib_asinh.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <math.h>
/****************************************************************************
* Public Functions
****************************************************************************/
#ifdef CONFIG_HAVE_DOUBLE
double asinh(double x)
{
double y;
double z = x * x;
if (z < 1E-9)
{
/* x - 1/6 * x^3 + 3/40 * x^5 - 5/112 * x^7 + ... */
y = x * (1 - z / 6.0);
}
else
{
y = log(x + sqrt(z + 1));
}
return y;
}
#endif