# gcd

## Purpose

Greatest common divisor.

## Synopsis

    g = gcd(a,b)
    [g,c,d] = gcd(a,b)

## Description

`g = gcd(a,b)` is the greatest common divisor of the integers `a` and `b`. By convention, `gcd(0,0)` returns a value of 0; all other inputs return positive integers.

`[g,c,d] = gcd(a,b)` also returns the scalars `c` and `d` such that `g = a`*`c+b`*`d`.

## Examples

    [g,c,d] = gcd(80,120)

    g =
        40

    c =
        -1

    d =
         1

## See Also

    lcm

## References

[1] Donald Knuth. The Art of Computer Programming, Vol. 2, Addison-Wesley:Reading MA, 1973. Section 4.5.2, Algorithm X.

(c) Copyright 1994 by The MathWorks, Inc.