From 82ba818ff456bcd6d56a06226e3f27e98fbb55c3 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Thu, 14 Aug 2025 22:58:58 -0500 Subject: removing all downloaded devdocs files --- devdocs/c/numeric%2Fmath%2Fatan2.html | 103 ---------------------------------- 1 file changed, 103 deletions(-) delete mode 100644 devdocs/c/numeric%2Fmath%2Fatan2.html (limited to 'devdocs/c/numeric%2Fmath%2Fatan2.html') diff --git a/devdocs/c/numeric%2Fmath%2Fatan2.html b/devdocs/c/numeric%2Fmath%2Fatan2.html deleted file mode 100644 index 94dcdd22..00000000 --- a/devdocs/c/numeric%2Fmath%2Fatan2.html +++ /dev/null @@ -1,103 +0,0 @@ -

atan2, atan2f, atan2l

Defined in header <math.h> 
float       atan2f( float y, float x );
-		 (1) (since C99) 
double      atan2( double y, double x );
-		 (2) 
long double atan2l( long double y, long double x );
-		 (3) (since C99) 
_Decimal32  atan2d32( _Decimal32 y, _Decimal32 x );
-		 (4) (since C23) 
_Decimal64  atan2d64( _Decimal64 y, _Decimal64 x );
-		 (5) (since C23) 
_Decimal128 atan2d128( _Decimal128 y, _Decimal128 x );
-		 (6) (since C23)
Defined in header <tgmath.h> 
#define atan2( y, x )
-		 (7) (since C99)
-1-6) Computes the arc tangent of y / x using the signs of arguments to determine the correct quadrant.
-7) Type-generic macro: If any argument has type long double, (3) (atan2l) is called. Otherwise, if any argument has integer type or has type double, (2) (atan2) is called. Otherwise, (1) (atan2f) is called.
- -

The functions (4-6) are declared if and only if the implementation predefines __STDC_IEC_60559_DFP__ (i.e. the implementation supports decimal floating-point numbers).

-		 (since C23)

Parameters

- -
x, y - floating-point value

Return value

If no errors occur, the arc tangent of y / x (arctan(y/x)) in the range [-π ; +π] radians, is returned.
Y argument
Return value
math-atan2.png
X argument

If a domain error occurs, an implementation-defined value is returned.

-

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

-

Error handling

Errors are reported as specified in math_errhandling.

-

Domain error may occur if x and y are both zero.

-

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

-

Notes

atan2(y, x) is equivalent to carg(x + I*y).

-

POSIX specifies that in case of underflow, y / x is the value returned, and if that is not supported, an implementation-defined value no greater than DBL_MIN, FLT_MIN, and LDBL_MIN is returned.

-

Example

#include <math.h>
-#include <stdio.h>
- 
-int main(void)
-{
-    // normal usage: the signs of the two arguments determine the quadrant
-    // atan2(1,1) = +pi/4, Quad I
-    printf("(+1,+1) cartesian is (%f,%f) polar\n", hypot( 1, 1), atan2( 1, 1));
-    // atan2(1, -1) = +3pi/4, Quad II
-    printf("(+1,-1) cartesian is (%f,%f) polar\n", hypot( 1,-1), atan2( 1,-1));
-    // atan2(-1,-1) = -3pi/4, Quad III
-    printf("(-1,-1) cartesian is (%f,%f) polar\n", hypot(-1,-1), atan2(-1,-1));
-    // atan2(-1,-1) = -pi/4, Quad IV
-    printf("(-1,+1) cartesian is (%f,%f) polar\n", hypot(-1, 1), atan2(-1, 1));
- 
-    // special values
-    printf("atan2(0, 0) = %f atan2(0, -0)=%f\n", atan2(0,0), atan2(0,-0.0));
-    printf("atan2(7, 0) = %f atan2(7, -0)=%f\n", atan2(7,0), atan2(7,-0.0));
-}

Output:

-
(+1,+1) cartesian is (1.414214,0.785398) polar
-(+1,-1) cartesian is (1.414214,2.356194) polar
-(-1,-1) cartesian is (1.414214,-2.356194) polar
-(-1,+1) cartesian is (1.414214,-0.785398) polar
-atan2(0, 0) = 0.000000 atan2(0, -0)=3.141593
-atan2(7, 0) = 1.570796 atan2(7, -0)=1.570796

References

See also

- - - - -
-
(C99)(C99)
 computes arc sine (\({\small\arcsin{x} }\)arcsin(x))
(function)
-
(C99)(C99)
 computes arc cosine (\({\small\arccos{x} }\)arccos(x))
(function)
-
(C99)(C99)
 computes arc tangent (\({\small\arctan{x} }\)arctan(x))
(function)
-
(C99)(C99)(C99)
 computes the phase angle of a complex number
(function)
C++ documentation for atan2
-

- © cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
- https://en.cppreference.com/w/c/numeric/math/atan2 -

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