ATAN(3) BSD Library Functions Manual ATAN(3)NAME
atan, atanf -- arc tangent function of one variable
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
atan(double x);
float
atanf(float x);
DESCRIPTION
The atan() and atanf() functions compute the principal value of the arc tangent of x in the range [-pi/2, +pi/2].
SEE ALSO acos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3), tan(3), tanh(3)STANDARDS
The atan() functions conforms to ANSI X3.159-1989 (``ANSI C89'').
BSD May 2, 1991 BSD

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ATAN(3) BSD Library Functions Manual ATAN(3)NAME
atan -- arc tangent function of one variable
SYNOPSIS
#include <math.h>
double
atan(double x);
long double
atanl(long double x);
float
atanf(float x);
DESCRIPTION
The atan() function computes the principal value of the arc tangent of x. The result is in the range [-pi/2, +pi/2].
SPECIAL VALUES
atan(+-0) returns +-0.
atan(+-infinity) returns +-pi/2
VECTOR OPERATIONS
If you need to apply the atan() function to SIMD vectors or arrays, using the following functions provided by the Accelerate.framework may
give significantly better performance:
#include <Accelerate/Accelerate.h>
vFloat vatanf(vFloat x);
void vvatanf(float *y, const float *x, const int *n);
void vvatan(double *y, const double *x, const int *n);
SEE ALSO acos(3), asin(3), atan2(3), cos(3), cosh(3), sin(3), sinh(3), tan(3), tanh(3), math(3) The atan() function conforms to ISO/IEC 9899:2011.
BSD December 11, 2006 BSD

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Hello All,
I need your help in the following situation. I have a 100x100 matrix with angle values ranging from -180 to 180. I would like to calculate the atan2 values for the above mentioned matrix, and the output should be in the same format (100x100 matrix).
I tried the following code:
... (3 Replies)