multiply.m

% import required modules for parse csv file
pkg load io

# load csv files
boxes_data = csv2cell("boxes.csv");
units_data = csv2cell("units.csv");

# target column for multiply
target_column = 3;

# delete headers
boxes_data(1,:) = [];
units_data(1,:) = [];

# checks arrays size
if (!size_equal(boxes_data, units_data))
  error("can't multiply, diff sizes")
endif

# output array
multiply_data = []

# get number of rows
[nr] = size(boxes_data);

# iterate each row
for i = 1:nr-1
  multiply_data(i,1) = boxes_data{i,target_column} .* units_data{i,target_column}
endfor

csvwrite ("multiplied.csv", multiply_data);