Error with IF statement "Subscript indices must either be real positive integers or logicals."

So I'm trying to do manipulate some data from a csv file but its throwing an error for my IF statement

Subscript indices must either be real positive integers or logicals.

Error in data_manip (line 23) if (logical(data(n)) > logical(on_peak)

onpeak = 1.4; data = csvread(datafile); charge_rate = 100;

for n = 0:20
  if (logical(data(n)) > logical(on_peak))
      %capLost = data(n) - on_peak;
      %cap = cap - capLost;
      %Load(n) = on_peak;
      %onoff(n) = 1;
  end
end

Answer 1

[Brahmadev]

Hi Joseph,

I understand that you would like to index through 'data' using the indexing variable 'n'. The error you're encountering is due to the incorrect usage of indices in the code. In MATLAB, indices start from 1, not 0. Therefore, when you use n = 0:20, the indices in the subsequent if statement are out of bounds. You can refer to the documentation link below to know more about array indexing.

https://www.mathworks.com/help/matlab/math/array-indexing.html

To fix this issue, you can modify the loop to start from 1 instead of 0. Additionally, you can remove the logical function calls in the if statement since they are unnecessary. You can modify the for loop as shown below:

for n = 1:20    
    if (data(n) > on_peak)
        % Calculation
    end
end

Hope this helps in resolving your issue!