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%2Fceil.html | 74 ++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 devdocs/c/numeric%2Fmath%2Fceil.html (limited to 'devdocs/c/numeric%2Fmath%2Fceil.html') diff --git a/devdocs/c/numeric%2Fmath%2Fceil.html b/devdocs/c/numeric%2Fmath%2Fceil.html new file mode 100644 index 00000000..76c99e95 --- /dev/null +++ b/devdocs/c/numeric%2Fmath%2Fceil.html @@ -0,0 +1,74 @@ +

ceil, ceilf, ceill

Defined in header <math.h> 
float       ceilf( float arg );
+		 (1) (since C99) 
double      ceil( double arg );
+		 (2) 
long double ceill( long double arg );
+		 (3) (since C99)
Defined in header <tgmath.h> 
#define ceil( arg )
+		 (4) (since C99)
+1-3) Computes the smallest integer value not less than arg.
+4) Type-generic macro: If arg has type long double, ceill is called. Otherwise, if arg has integer type or the type double, ceil is called. Otherwise, ceilf is called.

Parameters

+ +
arg - floating point value

Return value

If no errors occur, the smallest integer value not less than arg, that is ⌈arg⌉, is returned.

+
Return value
math-ceil.svg
Argument

Error handling

Errors are reported as specified in math_errhandling.

+

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

+

Notes

FE_INEXACT may be (but isn't required to be) raised when rounding a non-integer finite value.

+

The largest representable floating-point values are exact integers in all standard floating-point formats, so this function never overflows on its own; however the result may overflow any integer type (including intmax_t), when stored in an integer variable.

+

This function (for double argument) behaves as if (except for the freedom to not raise FE_INEXACT) implemented by

+
#include <math.h>
+#include <fenv.h>
+#pragma STDC FENV_ACCESS ON
+double ceil(double x)
+{
+    double result;
+    int save_round = fegetround();
+    fesetround(FE_UPWARD);
+    result = rint(x); // or nearbyint 
+    fesetround(save_round);
+    return result;
+}

Example

#include <math.h>
+#include <stdio.h>
+int main(void)
+{
+    printf("ceil(+2.4) = %+.1f\n", ceil(2.4));
+    printf("ceil(-2.4) = %+.1f\n", ceil(-2.4));
+    printf("ceil(-0.0) = %+.1f\n", ceil(-0.0));
+    printf("ceil(-Inf) = %+f\n",   ceil(-INFINITY));
+}

Possible output:

+
ceil(+2.4) = +3.0
+ceil(-2.4) = -2.0
+ceil(-0.0) = -0.0
+ceil(-Inf) = -inf

References

See also

+ + + + + +
+
(C99)(C99)
 computes largest integer not greater than the given value
(function)
+
(C99)(C99)(C99)
 rounds to nearest integer not greater in magnitude than the given value
(function)
+
(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99)
 rounds to nearest integer, rounding away from zero in halfway cases
(function)
+
(C99)(C99)(C99)
 rounds to an integer using current rounding mode
(function)
+
(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99)(C99)
 rounds to an integer using current rounding mode with
exception if the result differs
(function)
C++ documentation for ceil
+

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

+
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