How to solve matrix dimension must agree error in the following program.

d = 100;
r = mod(a,b);
for a = 2:1:d
    c = 0;
    for b = 1:1:a 
        if r == 0
            c = c+1;
        end
    end
    if c == 2
        fprintf('value of a = %d',b,c,d)
    end
end

[madhan ravi]

Values of a,b,c,d?

[PRASHIK GAIKWAD]

d = 100 and a = 2:1:d and b = 1:1:a c = 0 and if a/b = 0,then c = c+1,when c=2 then print value of a. That's the program I am trying to run.But I am getting an error saying Matrix dimension must agree

[madhan ravi]

you have defined a and b after using those variables?

>> d = 100;
r = mod(a,b);
for a = 2:1:d
    c = 0;
    for b = 1:1:a 
        if r == 0
            c = c+1;
        end
    end
    if c == 2
        fprintf('value of a = %d',b,c,d)
    end
end
Undefined function or variable 'b'.

Answer 1

[Basil C.]

Hi, according to what you stated in the comment there are a few mistakes i would like to points out

1. when b=1:1:a you only limit the value of b to be equal to [1,2] as it considers a to be a(1)

2. mod(a,b) requires the size of a and b to be the same which is clearly not since a has a size of 99 while b has only 2 elelments

Guessing from the code it seems like you are trying to write a code for generating prime numbers. Then I feel this is what you are looking for

 d = 100;
a = 2:1:d ;
c = 0 ;
for a = 2:1:d
    c = 0;
    for b = 1:1:a 
        r = mod(a,b);
        if r == 0
            c = c+1;
        end
    end
    if c == 2
        disp(['The value of a is = ',num2str(b)]);
    end
end