For some reason, the value in your excel file are stored as text instead of numeric values. The best solution is to fix the excel file. The following code shows how you can read your current excel file in MATLAB
% Proses membaca data latih dari excel
filename = 'CurahHujan.xlsx';
sheet = 2;
xlRange = 'D8:P19';
Data = table2cell(readtable(filename, 'Sheet', sheet, 'Range', xlRange));
Data = cellfun(@str2double, Data);
data_latih = Data(:,1:12)';
target_latih = Data(:,13)';
[m,n] = size(data_latih);
