error using randi: size inputs must be scalar

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George Amrhein
George Amrhein on 24 Apr 2017
Commented: George Amrhein on 24 Apr 2017
I apologize for the incredibly basic question I'm assuming it has something to do with Matlab versions but this old code that is very simple I cannot seem to make it work.
for n = 1:4
a{n} = randint(n,n,[0,9]);
b{n} = randint(n,n,[0,9]);
fprintf(n = %d:\n’, n), A = a{n}, B = b{n},
I changed randint to randi per recommendation of matlab.
I was able to make it work by manipulating the code to this.
for n=1:4
a{n}= randi(9,n)
b{n}= randi(9,n)
fprintf('n = %d:\n', n), A = a{n}, B = b{n},
now generates two 4x4 matrices with random numbers between [0,9].
Can somebody explain to me why though? The first formatting looks better than the second one logically.

Answers (3)

Joseph Cheng
Joseph Cheng on 24 Apr 2017
you actually want to do
for n=1:4
a{n}= randi(10,n)-1;
b{n}= randi(10,n)-1;
fprintf('n = %d:\n', n), A = a{n}, B = b{n},
as randi(9) is "Generate integer values from the uniform distribution on the set 1:9."
and what you have should be correct and does more than just 2 4x4 matrices. if you scroll up in the command window (as every calculation is displayed because there is no ';' at the end of the lines)
you should see that a and b is a cell array with varying size matrices in each cell
>> a
a =
[5] [2x2 double] [3x3 double] [4x4 double]
>> b
b =
[2] [2x2 double] [3x3 double] [4x4 double]

George Amrhein
George Amrhein on 24 Apr 2017
Sorry just trying to understand, your edit makes it so i can get the distribution on the set 0:9 in my matrix correct? instead of 1:9 as it was before

Walter Roberson
Walter Roberson on 24 Apr 2017
randi([0 9], n, n)

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