Question

In MATLAB I have a 1 X 20 column vector of string data in a file name A.txt.

%Input in A.txt:
60N
61N
50S
51S

Objective: to read the column of data as integers and represent N

as positive and S as negative.

So the output would be:

 60
 61
-50
-51

I have researched other posts, apply str2num double. I’m totally stuck.

Answer 1

Assuming your data is composed like in your example, you can try this:

[nums, directions] = textread('test.txt', '%d%s'); %# Read data from file
signs = ones(size(directions));                    %# Assume signs are positive
signs(strcmp(directions, 'S')) = -1;               %# Replace 'S' with negatives
result = nums(:) .* signs(:)                       %# Calculate result