atan, atanf, atanl
| Defined in header <math.h>
|
||
| float atanf( float arg ); |
(1) | (since 哋它亢99) |
| double atan( double arg ); |
(2) | |
| long double atanl( long double arg ); |
(3) | (since 哋它亢99) |
| _Decimal32 atand32( _Decimal32 arg ); |
(4) | (since 哋它亢23) |
| _Decimal64 atand64( _Decimal64 arg ); |
(5) | (since 哋它亢23) |
| _Decimal128 atand128( _Decimal128 arg ); |
(6) | (since 哋它亢23) |
| Defined in header <tgmath.h>
|
||
| #define atan( arg ) |
(7) | (since 哋它亢99) |
atanl) is called. Otherwise, if the argument has integer type or the type double, (2) (atan) is called. Otherwise, (1) (atanf) is called. If the argument is complex, then the macro invokes the corresponding complex function (MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 07 MINUTES 15 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 08 HOURS 07 MINUTES 14 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 08 HOURS 07 MINUTES 13 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE).|
The functions (4-6) are declared if and only if the implementation predefines |
(since 哋它亢23) |
Parameters
| arg | - | floating-point value |
Return value
If no errors occur, the arc tangent of arg (arctan(arg)) in the range [-| π |
| 2 |
| π |
| 2 |
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Error handling
Errors are reported as specified in MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 07 MINUTES 11 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE.
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- if the argument is ±0, it is returned unmodified;
- if the argument is +∞, +π/2 is returned;
- if the argument is -∞, -π/2 is returned;
- if the argument is NaN, NaN is returned.
Notes
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Example
#include <math.h> #include <stdio.h> int main(void) { MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 07 MINUTES 03 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("atan(1) = %f, 4*atan(1)=%f\n", atan(1), 4 * atan(1)); // special values MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 07 MINUTES 02 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("atan(Inf) = %f, 2*atan(Inf) = %f\n", atan(INFINITY), 2 * atan(INFINITY)); MYMEMORY WARNING: YOU USED ALL AVAILABLE FREE TRANSLATIONS FOR TODAY. NEXT AVAILABLE IN 08 HOURS 07 MINUTES 01 SECONDS VISIT HTTPS://MYMEMORY.TRANSLATED.NET/DOC/USAGELIMITS.PHP TO TRANSLATE MORE("atan(-0.0) = %+f, atan(+0.0) = %+f\n", atan(-0.0), atan(0)); }
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atan(1) = 0.785398, 4*atan(1)=3.141593 atan(Inf) = 1.570796, 2*atan(Inf) = 3.141593 atan(-0.0) = -0.000000, atan(+0.0) = +0.000000
References
- 哋它亢23 standard (ISO/IEC 9899:2023):
- 7.12.4.3 The atan functions (p: TBD)
- 7.25 Type-generic math <tgmath.h> (p: TBD)
- F.10.1.3 The atan functions (p: TBD)
- 哋它亢17 standard (ISO/IEC 9899:2018):
- 7.12.4.3 The atan functions (p: 174)
- 7.25 Type-generic math <tgmath.h> (p: 272-273)
- F.10.1.3 The atan functions (p: 378)
- 哋它亢11 standard (ISO/IEC 9899:2011):
- 7.12.4.3 The atan functions (p: 238-239)
- 7.25 Type-generic math <tgmath.h> (p: 373-375)
- F.10.1.3 The atan functions (p: 519)
- 哋它亢99 standard (ISO/IEC 9899:1999):
- 7.12.4.3 The atan functions (p: 219)
- 7.22 Type-generic math <tgmath.h> (p: 335-337)
- F.9.1.3 The atan functions (p: 456)
- 哋它亢89/C90 standard (ISO/IEC 9899:1990):
- 4.5.2.3 The atan function
See also
| (哋它亢99)(哋它亢99) |
computes arc tangent, using signs to determine quadrants (function) |
| (哋它亢99)(哋它亢99) |
computes arc sine (arcsin(x)) (function) |
| (哋它亢99)(哋它亢99) |
computes arc cosine (arccos(x)) (function) |
| (哋它亢99)(哋它亢99) |
computes tangent (tan(x)) (function) |
| (哋它亢99)(哋它亢99)(哋它亢99) |
computes the complex arc tangent (function) |