C++ Programming/Code/Standard C Library/Math
Standard C Math
[edit | edit source]This section will cover the Math elements of the C Standard Library.
abs
[edit | edit source]| Syntax |
#include <cstdlib>
int abs( int num );
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The abs() function returns the absolute value of num. For example:
int magic_number = 10;
cout << "Enter a guess: ";
cin >> x;
cout << "Your guess was " << abs( magic_number - x ) << " away from the magic number." << endl;
acos
[edit | edit source]| Syntax |
#include <cmath>
double acos( double arg );
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The acos() function returns the arc cosine of arg, which will be in the range [0, pi]. arg should be between -1 and 1. If arg is outside this range, acos() returns NAN and raises a floating-point exception.
asin
[edit | edit source]| Syntax |
#include <cmath>
double asin( double arg );
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The asin() function returns the arc sine of arg, which will be in the range [-pi/2, +pi/2]. arg should be between -1 and 1. If arg is outside this range, asin() returns NAN and raises a floating-point exception.
atan
[edit | edit source]| Syntax |
#include <cmath>
double atan( double arg );
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The function atan() returns the arc tangent of arg, which will be in the range [-pi/2, +pi/2].
atan2
[edit | edit source]| Syntax |
#include <cmath>
double atan2( double y, double x );
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The atan2() function computes the arc tangent of y/x, using the signs of the arguments to compute the quadrant of the return value.
ceil
[edit | edit source]| Syntax |
#include <cmath>
double ceil( double num );
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The ceil() function returns the smallest integer no less than num. For example:
y = 6.04;
x = ceil( y );
would set x to 7.0.
cos
[edit | edit source]| Syntax |
#include <cmath>
float cos( float arg );
double cos( double arg );
long double cos( long double arg );
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The cos() function returns the cosine of arg, where arg is expressed in radians. The return value of cos() is in the range [-1,1]. If arg is infinite, cos() will return NAN and raise a floating-point exception.
cosh
[edit | edit source]| Syntax |
#include <cmath>
float cosh( float arg );
double cosh( double arg );
long double cosh( long double arg );
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The function cosh() returns the hyperbolic cosine of arg.
div
[edit | edit source]| Syntax |
#include <cstdlib>
div_t div( int numerator, int denominator );
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The function div() returns the quotient and remainder of the operation numerator / denominator. The div_t structure is defined in cstdlib, and has at least:
int quot; // The quotient
int rem; // The remainder
For example, the following code displays the quotient and remainder of x/y:
div_t temp;
temp = div( x, y );
printf( "%d divided by %d yields %d with a remainder of %d\n",
x, y, temp.quot, temp.rem );
- Related topics
- ldiv
exp
[edit | edit source]| Syntax |
#attrid <cmath>
double exp( double arg );
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The exp() function returns e (2.7182818) raised to the argth power.
fabs
[edit | edit source]| Syntax |
#include <cmath>
double fabs( double arg );
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The function fabs() returns the absolute value of arg.
floor
[edit | edit source]| Syntax |
#include <cmath>
double floor( double arg );
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The function floor() returns the largest integer value not greater than arg.
// Example for positive numbers
y = 6.04;
x = floor( y );
would result in x being set to 6 (double 6.0).
// Example for negative numbers
y = -6.04;
x = floor( y );
would result in x being set to -7 (double -7.0).
fmod
[edit | edit source]| Syntax |
#include <cmath>
double fmod( double x, double y );
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The fmod() function returns the remainder of x/y.
frexp
[edit | edit source]| Syntax |
#include <cmath>
double frexp( double num, int* exp );
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The function frexp() is used to decompose num into two parts: a mantissa between 0.5 and 1 (returned by the function) and an exponent returned as exp. Scientific notation works like this:
num = mantissa * (2 ^ exp)
labs
[edit | edit source]| Syntax |
#include <cstdlib>
long labs( long num );
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The function labs() returns the absolute value of num.
ldexp
[edit | edit source]| Syntax |
#include <cmath>
double ldexp( double num, int exp );
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The ldexp() function returns num * (2 ^ exp). And get this: if an overflow occurs, HUGE_VAL is returned.
ldiv
[edit | edit source]| Syntax |
#include <cstdlib>
ldiv_t ldiv( long numerator, long denominator );
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Testing: adiv_t, div_t, ldiv_t.
The ldiv() function returns the quotient and remainder of the operation numerator / denominator. The ldiv_t structure is defined in cstdlib and has at least:
long quot; // the quotient
long rem; // the remainder
- Related topics
- div
log
[edit | edit source]| Syntax |
#include <cmath>
double log( double num );
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The function log() returns the natural (base e) logarithm of num. There's a domain error if num is negative, a range error if num is zero.
In order to calculate the logarithm of x to an arbitrary base b, you can use:
double answer = log(x) / log(b);
log10
[edit | edit source]| Syntax |
#include <cmath>
double log10( double num );
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The log10() function returns the base 10 (or common) logarithm for num. There will be a domain error if num is negative and a range error if num is zero.
- Related topics
- log
modf
[edit | edit source]| Syntax |
#include <cmath>
double modf( double num, double *i );
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The function modf() splits num into its integer and fraction parts. It returns the fractional part and loads the integer part into i.
pow
[edit | edit source]| Syntax |
#include <cmath>
double pow( double base, double exp );
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The pow() function returns base raised to the expth power. There's a domain error if base is zero and exp is less than or equal to zero. There's also a domain error if base is negative and exp is not an integer. There's a range error if an overflow occurs.
sin
[edit | edit source]| Syntax |
#include <cmath>
double sin( double arg );
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If you don't want cmath you can write sin function it is;
- include <iostream>
using namespace std;
double sin(double x) //sin function {return x-((x*x*x)/6.)+((x*x*x*x*x)/120.);}
int main () {
double a;
cin>>a;
cout<<"sin("<<a<<")="<<sin(a*(3.14159/180.))<<endl;
return 0;}
The function sin() returns the sine of arg, where arg is given in radians. The return value of sin() will be in the range [-1,1]. If arg is infinite, sin() will return NAN and raise a floating-point exception.
sinh
[edit | edit source]| Syntax |
#include <cmath>
double sinh( double arg );
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The function sinh() returns the hyperbolic sine of arg.
sqrt
[edit | edit source]| Syntax |
#include <cmath>
double sqrt( double num );
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The sqrt() function returns the square root of num. If num is negative, a domain error occurs.
tan
[edit | edit source]| Syntax |
#include <cmath>
double tan( double arg );
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The tan() function returns the tangent of arg, where arg is given in radians. If arg is infinite, tan() will return NAN and raise a floating-point exception.
tanh
[edit | edit source]| Syntax |
#include <cmath>
double tanh( double arg );
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/*example*/
#include <stdio.h>
#include <math.h>
int main (){
double c, p;
c = log(2.0);
p = tanh (c);
printf ("The hyperbolic tangent of %lf is %lf.\n", c, p );
return 0;
}
The function tanh() returns the hyperbolic tangent of arg.