# 2.1.16.1.1 abs

## Description

Absolute value of a floating-point (double). This function is implemented in internal.c as a compatibility function for the labtalk version of abs(x) function. Please note that this function will simply call the fabs(x) function.

## Syntax

double abs( double x )

int abs( int n )

## Parameters

x
[input] double value whose absolute value is returned

n
[input] integer value whose absolute value is returned

## Return

Return the absolute value of a double.

Returns the absolute value of an integer.

## Examples

EX1

void    abs_ex1()
{
double        x = -5.9;
double        val = abs(x);

printf("abs(%f) = %f\n", x, val);
}

EX2

// This program computes and displays the absolute values of several numbers.
#include <origin.h>
int test_abs()
{
int nn;
nn = abs( 0 );
out_int("abs(0)=", nn);        //output should be abs(0)=0
ASSERT( nn == 0 );
nn = abs( -9 );
out_int("abs(-9)=", nn);    //output should be abs(-9)=9
ASSERT( nn == 9 );
nn = abs( 200 );
out_int("abs(200)=", nn);    //output should be abs(200)=200
ASSERT( nn == 200 );
nn = abs( -3.5 );
out_int("abs(-3.5)=", nn);    //output should be abs(-3.5)=3
ASSERT( nn == 3 );
return 1;
}

## Remark

Absolute value (for integers). Note that this built-in C library abs function returns an int while the LabTalk abs function returns a double. The standard C library function fabs should typically used for doubles. To making it easier for Origin users, especially in defining fitting functions, an Origin C version of abs(double) has been added into internal.c, which is compiled automatically on Origin startup.