maximum value array of multiple arrays

Suppose I have many arrays or vectors of data

A, B, C ....etc

I can create an array which has the maximum and minimum values using the max min function when I compare two arrays:

A = [1 2 3];
B = [3 2 1];
maximum = max(A,B)
minimum = min(A,B)

But for a third, fourth fifth array, this does not seem to work:

A = [1 2 3];
B = [3 2 1];
C = [2 3 2];
maximum = max(A,B,C)
minimum = min(A,B,C)

I am looking for a simple method to create an array of maximum and minimum values for many input arrays - I guess I am missing something obvious? I am working with many arrays (many hundreds) which each contain tens of thousands of data points. I can write a loop which finds the maximum of A&B and C&D then finds the maximum of AB and CD; then the maximum of ABCD and EFGH... and so on; but this seems labourious.

thanks in advance.

[Stephen23]

" I am working with many arrays (many hundreds) which each contain tens of thousands of data points."

Having lots of individual variables that you now want to process together is a sign that they should be stored in one variable. Putting the data into one variable makes the solution to your original question a trivial one-line operation, and hugely simplifies any other processing of the data.

"I can write a loop which finds the maximum of A&B and C&D then finds the maximum of AB and CD; then the maximum of ABCD and EFGH... and so on; but this seems labourious."

A loop is not so bad. Just make sure to avoid dynamically accessing the variable names!:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

Answer 1

[Stephen23]

Put the data into one array and use the third dim argument:

arr = cat(3,A,B,C,...)
min(arr,[],3)
max(arr,[],3)

If arr is too large to fit into your computer's memory, then either:

• use a loop,
• concatenate subsets of the arrays at a time, using min / max with the dim argument each time.