remquo, remquof, remquol
| Defined in header <math.h>
|
||
| float remquof( float x, float y, int *quo ); |
(1) | (since 哋它亢99) |
| double remquo( double x, double y, int *quo ); |
(2) | (since 哋它亢99) |
| long double remquol( long double x, long double y, int *quo ); |
(3) | (since 哋它亢99) |
| Defined in header <tgmath.h>
|
||
| #define remquo( x, y, quo ) |
(4) | (since 哋它亢99) |
remquol is called. Otherwise, if any non-pointer argument has integer type or has type double, remquo is called. Otherwise, remquof is called.Parameters
| x, y | - | floating-point values |
| quo | - | pointer to an integer value to store the sign and some bits of x/y |
Return value
If successful, returns the floating-point remainder of the division x/y as defined in MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 34 MINUTES 02 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE, and stores, in *quo, the sign and at least three of the least significant bits of x/y (formally, stores a value whose sign is the sign of x/y and whose magnitude is congruent modulo 2n
to the magnitude of the integral quotient of x/y, where n is an implementation-defined integer greater than or equal to 3).
If y is zero, the value stored in *quo is unspecified.
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If y is zero, but the domain error does not occur, zero is returned.
Error handling
Errors are reported as specified in MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 58 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE.
Domain error may occur if y is zero.
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- The current MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 55 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE has no effect.
- MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 54 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE is never raised
- If x is ±∞ and y is not NaN, NaN is returned and MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 53 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE is raised
- If y is ±0 and x is not NaN, NaN is returned and MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 52 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE is raised
- If either x or y is NaN, NaN is returned
Notes
MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 51 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE that a domain error occurs if x is infinite or y is zero.
This function is useful when implementing periodic functions with the period exactly representable as a floating-point value: when calculating sin(πx) for a very large x, calling MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 50 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE directly may result in a large error, but if the function argument is first reduced with remquo, the low-order bits of the quotient may be used to determine the sign and the octant of the result within the period, while the remainder may be used to calculate the value with high precision.
On some platforms this operation is supported by hardware (and, for example, on Intel CPU, FPREM1 leaves exactly 3 bits of precision in the quotient).
Example
#include <fenv.h> #include <math.h> #include <stdio.h> #ifndef __GNUC__ #pragma STDC FENV_ACCESS ON #endif double cos_pi_x_naive(double x) { const double pi = MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 49 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(-1); return MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 47 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(pi * x); } // the period is 2, values are (0;0.5) positive, (0.5;1.5) negative, (1.5,2) positive double cos_pi_x_smart(double x) { const double pi = MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 46 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(-1); int extremum; double rem = remquo(x, 1, &extremum); extremum = (unsigned)extremum % 2; // keep 1 bit to determine nearest extremum return extremum ? -MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 45 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(pi * rem) : MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 44 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(pi * rem); } int main(void) { MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 43 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("cos(pi * 0.25) = %f\n", cos_pi_x_naive(0.25)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 41 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("cos(pi * 1.25) = %f\n", cos_pi_x_naive(1.25)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 40 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("cos(pi * 1000000000000.25) = %f\n", cos_pi_x_naive(1000000000000.25)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 39 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("cos(pi * 1000000000001.25) = %f\n", cos_pi_x_naive(1000000000001.25)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 38 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("cos(pi * 1000000000000.25) = %f\n", cos_pi_x_smart(1000000000000.25)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 37 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("cos(pi * 1000000000001.25) = %f\n", cos_pi_x_smart(1000000000001.25)); // error handling MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 35 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 34 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE); int quo; MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 33 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("remquo(+Inf, 1) = %.1f\n", remquo(INFINITY, 1, &quo)); if (MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 32 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 31 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE)) MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 07 HOURS 33 MINUTES 30 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE(" FE_INVALID raised"); }
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cos(pi * 0.25) = 0.707107
cos(pi * 1.25) = -0.707107
cos(pi * 1000000000000.25) = 0.707123
cos(pi * 1000000000001.25) = -0.707117
cos(pi * 1000000000000.25) = 0.707107
cos(pi * 1000000000001.25) = -0.707107
remquo(+Inf, 1) = -nan
FE_INVALID raisedReferences
- 哋它亢23 standard (ISO/IEC 9899:2023):
- 7.12.10.3 The remquo functions (p: TBD)
- 7.25 Type-generic math <tgmath.h> (p: TBD)
- F.10.7.3 The remquo functions (p: TBD)
- 哋它亢17 standard (ISO/IEC 9899:2018):
- 7.12.10.3 The remquo functions (p: 186)
- 7.25 Type-generic math <tgmath.h> (p: 272-273)
- F.10.7.3 The remquo functions (p: 385)
- 哋它亢11 standard (ISO/IEC 9899:2011):
- 7.12.10.3 The remquo functions (p: 255)
- 7.25 Type-generic math <tgmath.h> (p: 373-375)
- F.10.7.3 The remquo functions (p: 529)
- 哋它亢99 standard (ISO/IEC 9899:1999):
- 7.12.10.3 The remquo functions (p: 236)
- 7.22 Type-generic math <tgmath.h> (p: 335-337)
- F.9.7.3 The remquo functions (p: 465)
See also
| (哋它亢99) |
computes quotient and remainder of integer division (function) |
| (哋它亢99)(哋它亢99) |
computes remainder of the floating-point division operation (function) |
| (哋它亢99)(哋它亢99)(哋它亢99) |
computes signed remainder of the floating-point division operation (function) |