diff options
author | Nicholas Noll <nbnoll@eml.cc> | 2021-12-05 16:16:21 -0800 |
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committer | Nicholas Noll <nbnoll@eml.cc> | 2021-12-05 16:16:21 -0800 |
commit | 07e77936d535e58b0aeb4f2a11400c1050556739 (patch) | |
tree | fb50fad6436ecbc159505bee73a92cd289b99a07 /src/base/math/tanh.c | |
parent | b48327d357e0818d1a6ae2a064cfa7d1567e1242 (diff) |
Feat: added math library
Used Plan9's libc as starting point. This cleans up dangling references
due to loss of libc.
Diffstat (limited to 'src/base/math/tanh.c')
-rw-r--r-- | src/base/math/tanh.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/src/base/math/tanh.c b/src/base/math/tanh.c new file mode 100644 index 0000000..81e428a --- /dev/null +++ b/src/base/math/tanh.c @@ -0,0 +1,25 @@ +#include <u.h> +#include <base.h> + +/* + tanh(arg) computes the hyperbolic tangent of its floating + point argument. + + sinh and cosh are called except for large arguments, which + would cause overflow improperly. + */ + +double +math·tanh(double arg) +{ + + if(arg < 0) { + arg = -arg; + if(arg > 21) + return -1; + return -math·sinh(arg)/math·cosh(arg); + } + if(arg > 21) + return 1; + return math·sinh(arg)/math·cosh(arg); +} |