From 754bbf7a25a8dda49b5d08ef0d0443bbf5af0e36 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Sun, 7 Apr 2024 13:41:34 -0500 Subject: new repository --- devdocs/c/numeric%2Fmath%2Ffdim.html | 63 ++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 devdocs/c/numeric%2Fmath%2Ffdim.html (limited to 'devdocs/c/numeric%2Fmath%2Ffdim.html') diff --git a/devdocs/c/numeric%2Fmath%2Ffdim.html b/devdocs/c/numeric%2Fmath%2Ffdim.html new file mode 100644 index 00000000..4d64f3ac --- /dev/null +++ b/devdocs/c/numeric%2Fmath%2Ffdim.html @@ -0,0 +1,63 @@ +

fdim, fdimf, fdiml

Defined in header <math.h> 
float       fdimf( float x, float y );
+		 (1) (since C99) 
double      fdim( double x, double y );
+		 (2) (since C99) 
long double fdiml( long double x, long double y );
+		 (3) (since C99)
Defined in header <tgmath.h> 
#define fdim( x, y )
+		 (4) (since C99)
+1-3) Returns the positive difference between x and y, that is, if x>y, returns x-y, otherwise (if x≤y), returns +0.
+4) Type-generic macro: If any argument has type long double, fdiml is called. Otherwise, if any argument has integer type or has type double, fdim is called. Otherwise, fdimf is called.

Parameters

+ +
x, y - floating point value

Return value

If successful, returns the positive difference between x and y.

+

If a range error due to overflow occurs, +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL is returned.

+

If a range error due to underflow occurs, the correct value (after rounding) is returned.

+

Error handling

Errors are reported as specified in math_errhandling.

+

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

+

Notes

Equivalent to fmax(x-y, 0) except for the NaN handling requirements.

+

Example

#include <stdio.h>
+#include <math.h>
+#include <errno.h>
+#include <fenv.h>
+// #pragma STDC FENV_ACCESS ON
+int main(void)
+{
+    printf("fdim(4, 1) = %f, fdim(1, 4)=%f\n", fdim(4,1), fdim(1,4));
+    printf("fdim(4,-1) = %f, fdim(1,-4)=%f\n", fdim(4,-1), fdim(1,-4));
+    //error handling
+    errno = 0; feclearexcept(FE_ALL_EXCEPT);
+    printf("fdim(1e308, -1e308) = %f\n", fdim(1e308, -1e308));
+    if(errno == ERANGE) perror("    errno == ERANGE");
+    if(fetestexcept(FE_OVERFLOW)) puts("    FE_OVERFLOW raised");
+}

Possible output:

+
fdim(4, 1) = 3.000000, fdim(1, 4)=0.000000
+fdim(4,-1) = 5.000000, fdim(1,-4)=5.000000
+fdim(1e308, -1e308) = inf
+    errno == ERANGE: Numerical result out of range
+    FE_OVERFLOW raised

References

See also

+ + +
+
(C99)
 computes absolute value of an integral value (\(\small{|x|}\)|x|)
(function)
+
(C99)(C99)(C99)
 determines larger of two floating-point values
(function)
C++ documentation for fdim
+

+ © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
+ https://en.cppreference.com/w/c/numeric/math/fdim +

+
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