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%2Fremainder.html | 87 +++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 devdocs/c/numeric%2Fmath%2Fremainder.html (limited to 'devdocs/c/numeric%2Fmath%2Fremainder.html') diff --git a/devdocs/c/numeric%2Fmath%2Fremainder.html b/devdocs/c/numeric%2Fmath%2Fremainder.html new file mode 100644 index 00000000..1abb2995 --- /dev/null +++ b/devdocs/c/numeric%2Fmath%2Fremainder.html @@ -0,0 +1,87 @@ +

remainder, remainderf, remainderl

Defined in header <math.h> 
float       remainderf( float x, float y );
+		 (1) (since C99) 
double      remainder( double x, double y );
+		 (2) (since C99) 
long double remainderl( long double x, long double y );
+		 (3) (since C99)
Defined in header <tgmath.h> 
#define remainder( x, y )
+		 (4) (since C99)
+1-3) Computes the IEEE remainder of the floating point division operation x/y.
+4) Type-generic macro: If any argument has type long double, remainderl is called. Otherwise, if any argument has integer type or has type double, remainder is called. Otherwise, remainderf is called.

The IEEE floating-point remainder of the division operation x/y calculated by this function is exactly the value x - n*y, where the value n is the integral value nearest the exact value x/y. When |n-x/y| = ½, the value n is chosen to be even.

+

In contrast to fmod(), the returned value is not guaranteed to have the same sign as x.

+

If the returned value is 0, it will have the same sign as x.

+

Parameters

+ +
x, y - floating point values

Return value

If successful, returns the IEEE floating-point remainder of the division x/y as defined above.

+

If a domain error occurs, an implementation-defined value is returned (NaN where supported).

+

If a range error occurs due to underflow, the correct result is returned.

+

If y is zero, but the domain error does not occur, zero is returned.

+

Error handling

Errors are reported as specified in math_errhandling.

+

Domain error may occur if y is zero.

+

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

+

Notes

POSIX requires that a domain error occurs if x is infinite or y is zero.

+

fmod, but not remainder is useful for doing silent wrapping of floating-point types to unsigned integer types: (0.0 <= (y = fmod(rint(x), 65536.0)) ? y : 65536.0 + y) is in the range [-0.0 .. 65535.0], which corresponds to unsigned short, but remainder(rint(x), 65536.0) is in the range [-32767.0, +32768.0], which is outside of the range of signed short.

+

Example

#include <stdio.h>
+#include <math.h>
+#include <fenv.h>
+ 
+#pragma STDC FENV_ACCESS ON
+int main(void)
+{
+    printf("remainder(+5.1, +3.0) = %.1f\n", remainder(5.1,3));
+    printf("remainder(-5.1, +3.0) = %.1f\n", remainder(-5.1,3));
+    printf("remainder(+5.1, -3.0) = %.1f\n", remainder(5.1,-3));
+    printf("remainder(-5.1, -3.0) = %.1f\n", remainder(-5.1,-3));
+ 
+    // special values
+    printf("remainder(-0.0, 1.0) = %.1f\n", remainder(-0.0, 1));
+    printf("remainder(+5.1, Inf) = %.1f\n", remainder(5.1, INFINITY));
+ 
+    // error handling
+    feclearexcept(FE_ALL_EXCEPT);
+    printf("remainder(+5.1, 0) = %.1f\n", remainder(5.1, 0));
+    if(fetestexcept(FE_INVALID)) puts("    FE_INVALID raised");
+}

Output:

+
remainder(+5.1, +3.0) = -0.9
+remainder(-5.1, +3.0) = 0.9
+remainder(+5.1, -3.0) = -0.9
+remainder(-5.1, -3.0) = 0.9
+remainder(+0.0, 1.0) = 0.0
+remainder(-0.0, 1.0) = -0.0
+remainder(+5.1, Inf) = 5.1
+remainder(+5.1, 0) = -nan
+    FE_INVALID raised

References

See also

+ + + +
+
(C99)
 computes quotient and remainder of integer division
(function)
+
(C99)(C99)
 computes remainder of the floating-point division operation
(function)
+
(C99)(C99)(C99)
 computes signed remainder as well as the three last bits of the division operation
(function)
C++ documentation for remainder
+

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

+
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