## Linux and UNIX Man Pages

Test Your Knowledge in Computers #139
Difficulty: Easy
The early Unix environment and the client-server program networking model were key elements in the development of the Internet.
True or False?

# atan(3) [php man page]

```ATAN(3) 								 1								   ATAN(3)

atan - Arc tangent

SYNOPSIS
float atan (float  \$arg)

DESCRIPTION
Returns  the  arc  tangent of \$arg in radians. atan(3) is the complementary function of tan(3), which means that a==tan(atan(a)) for every
value of a that is within atan(3)'s range.

PARAMETERS
o \$arg
- The argument to process

RETURN VALUES
The arc tangent of \$arg in radians.

tan(3), atanh(3), asin(3), acos(3).

PHP Documentation Group 														   ATAN(3)```

## Check Out this Related Man Page

```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);

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```

## Satan

Help!! Anybody out there had much to do with setting up SATAN (Security Admin Tool for Analyzing Networks)? I need help setting it up on a Linux box.

## Satan

has anyone had any experience with SATAN? and can fill me in with some quick pro/cons and maybe some screenshots? thanks email removed - read the rules

## usage of atan

Hi All, can anybody explain me the syntax and usage of "atan" command? Thanks in advance.

## Atan2 function in awk

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: ...