Error using .* Matrix dimensions must agree.

hi i am new and need help with this, try to follow the steps of the program but it keeps coming this error.

please help!

Error using .* Matrix dimensions must agree.

m=8;
n=2^m-1;
k=233;
t=(n-k)/2;
nw=1;
msgw=gf(randint(nw,k,2^m),m);
c=rsenc(msgw,n,k);
*noise=(1+randint(nw,k,2^m-1)).*randerr(nw,n,t);*
cnoisy=c+noise;
[dc,nerrs,corrcode]=rsdec(cnoisy,n,k);
isequal(dc,msgw)& isequal(corrcode,c);
nerrs;

Answer 1

[Walter Roberson]

In randint(nw,k,2^m-1), 2^m-1 is the same as n, so this is the same as randint(nw,k,n) . That will generate a k by n array of random integers in the range 1 to nw.

randerr(nw,n,t) will generate an nw by n array with t non-zero entries per line.

You attempt to use .* to multiply those two arrays. In order to use .* the arrays must be the same size or at least one of the operands must be a scalar.

We are comparing a k by n array in size to an nw by n array. Those are the same size only if k == nw . Which it certainly does not.