How to find double output?

import java.math.*;

>> p=BigInteger('11');

>> m=BigInteger('2');

>> [A,B]=m.gcd(p);

Error using java.math.BigInteger/gcd

Java methods cannot be called with multiple output arguments

How to resolve this issue? I need both A and B.

Thanking in anticipation

[Rik]

What is the second output? There might be a way to compute it separately.

[Ammy]

[A,B]=gcd(2,11)

A=1; B=-5;

[Ammy]

It works when the integers are not in the above format, but showing error with the above format.

[Rik]

Ok, I admit I wasn't clear enough with my question: what is the second output supposed to be in a more general sense? There is only 1 greatest common denominator, so what second value could you extract from it?

I have no experience interfacing with Java (except for copy-paste examples), so I can only help you to try to find a method to calculate the second output another way.

[AndresVar]

@Ammy gcd usually just gives 1 output. The matlab function with more than 1 output is returning the Bezout coefficients. Which you can calculate yourself.

You can see Matlab calculates it: edit gcd

Or you can find the algorithm online

[Ammy]

@Rik Thank you ver much!

I want to extract the following

[A,B] = gcd(m,p);

if A =1 then

a = mod(B,p)

otherwise a=0

I want to find a which depends on both A and B

[Ammy]

@AndresVar, thank you very much but I want to deal with both the outputs.

Answer 1

[Walter Roberson]

 import java.math.*;
 p = BigInteger('11');
 m = BigInteger('2');
 A = m.gcd(p)

A =

1

 B = m.modInverse(p)

B =

6

m.multiply(B).mod(p)

ans =

1

[Ammy]

@Walter Roberson Thank you very much, Yes I had tried this, but can you please help me is there any way to deal it in a function.

If I have a function inverse.m

import java.math.*;
p = BigInteger('11');
m = BigInteger('2');
ans= m.inverse(p);

where

function a = inverse(b, p)
b = mod(b, p);
[A,B] = gcd(b, p);
if A==1
    a = mod(B,p);
else
    a = 0;
end
end

[Walter Roberson]

 import java.math.*;
 p = BigInteger('11');
 m = BigInteger('2');
 a = inverse(m, p)

a =

6

 
 %cross-check
 cross_check = m.multiply(a).mod(p)

cross_check =

1

 
function a = inverse(b, p)
    import java.math.*;
    A = b.gcd(p);
    if A == BigInteger('1')
        a = b.modInverse(p);
    else
        a = BigInteger('0');
    end
end

[Ammy]

Thank you very much!