How do I create a for loop in MATLAB for this?

Greeting everyone.

I have a these matrix: A is by the order of 10 by 3.

I want to do this calculation: B = (A-min(A))/[max(A)-min(A)]

After that I want B to be by the order of 10 by 3.

Is there a way where I can do a loop of this?

[Walter Roberson]

Sure. You can deliberately create a loop or two to find the max and min, and you can deliberately create a loop or two to rescale. You do not need to do those things, but you can.

The trick for the vectorized form is that by default max and min work over only one dimension of a multidimensional array. See the documentation for how to change that to process all dimensions.

Answer 1

[James Tursa]

If you want to use the overall min and max, then just use A(:) for the calculations. E.g.,

B = (A-min(A(:)))/[max(A(:))-min(A(:))];

A(:) is shorhand for reshaping the variable into a column vector.

[Chloe Sim]

Hello, thank you for the quick response. But how do I get the individual values and store into a matrix of 10 rows and 3 columns?

[James Tursa]

B will be the same size as A. Did you try the code?

[Chloe Sim]

Hello, yes i tried the code. But i needed the max and min of each column, not the entire matrix.

[Walter Roberson]

Are you still required to do a loop for it? (If so, then go ahead and write a loop)

[Chloe Sim]

Actually, I was guessing using loop will be the best option in the case. But I not sure, how to go about and do it.

[Walter Roberson]

You can find the per-row min using min(A, [], 2) and you can find the per-row max using similar code. You can do the subtractions . But you should change the division from / to ./

The resulting expression should handle the entire matrix with no loops.

Answer 2

[Steven Lord]

Use the normalize function with the 'range' method. No for loop is required.

[Walter Roberson]

Or use the older, confusingly-named, mat2gray()