Setting columns in mat.newfromlabel()

[dcuny]

In Matrix.lua, the routine mat.newfromlabel has a loop using grid.cols.

However, grid.cols is set to 1. And the the variable j is never used:

--New matrix from a given label, for classification
function mat.newfromlabel(rows,label_index)
  local grid ={}
  grid.rows = rows
  grid.cols = 1
  grid.matrix = {}
  local j = 1
  for i=1,rows do
    grid.matrix[i] = {}
    for k=1,grid.cols do
      if i == label_index then
        grid.matrix[i][k] = 1
      else
        grid.matrix[i][k] = 0
      end
    end
  end
    return grid
  end

It looks like this code is a rewrite of the prior function, ** mat.newrdn()**. Perhaps editing out the unused code would make it more clear what the routine is doing:

--New matrix from a given label, for classification
function mat.newfromlabel(rows,label_index)
  
  -- create the grid object
  local grid ={}
  
  -- set the attributes
  grid.rows = rows
  grid.cols = 1

  -- create a matrix with a single column
  local matrix = {}
  for i=1,rows do
    matrix[i] = {0}
  end

  -- set the column with at label_index to 1
  matrix[label_index][1] = 1
  
  -- assign the matrix to the grid
  grid.matrix = matrix

  return grid
end