How do I derive a linear equation for wind speed between 13km/h –50km/h using “if-else”?

for i = 1: length(Wind_Year)
    
  if WindLight = nnz((Wind_Year >= 13) & (Wind_Year < 50));
      
      
      Power = m * x + c;
      Power = m * WindLight + c;
      
      Power1 =[Power1; Power];
      Day1 = [Day1; i];
      
      
  elseif WindHeavy = nnz((Wind_Year >= 50) & (Wind_Year <= 100));
      
      Power = m * x + c;
      Power = m * WindHeavy + c;
      
      Power2 = [Power2; Power];
      Day2 = [Day2; i];
      
  
  end

end

The data (13 - 50) and (50 - 100) is coming from 12 spreadsheets.

Answer 1

[Andreas Bernatzky]

you have to index Wind_Year with your increment i.

For example Wind_Year(i) but heavily depends on what type of container your Wind_Year variable belongs to (Table,Vector,Cell...)

[Thomas Portsmouth]

source_directory = 'C:\Users\thoma\OneDrive\Desktop\Project 1';
source_file = dir(fullfile(source_directory, '*.csv'));


Wind_Year = [];

for i = 1: 12 
    file_name = fullfile(source_directory,source_file(i).name);
    file_data = xlsread(file_name);
    
    Wind_Month = file_data(:, 7);
    Wind_Year = [Wind_Year; Wind_Month];
end

This is where my Wind_Year is coming from, its 12 spredsheets of data.

[Andreas Bernatzky]

Hello Thomas,

sorry for the late reply. Maybe you can attach one of the (shorter) excel-Sheets?

Than I can have a better look on it.

Your code looks ok to me for iterating over all sheets.