Generating isometric grid for tileset in Corona SDK - lua

Question

I imported an isometric map made in tiled to Corona SDK and am now trying to overlay a grid layer. I've done a lot of reading into isometric grids but it seems they all reference tilesets where the height is half the width. (ex. 128x64px ). I am using a tileset that requires the grid to be 256x149px and I think I have to edit the grid generation function to accommodate the change. Any help would be greatly appreciated!
Screenshot of the issue (Using original Vectors):
Original Vectors: https://image.ibb.co/emXpQR/Screen_Shot_2017_12_18_at_1_35_19_PM.png
Edited Vectors (the ones commented out in code): https://image.ibb.co/ikxOkR/Screen_Shot_2017_12_18_at_1_35_54_PM.png
Grid Generation Code:
function drawGrid()
for row = 0, 16 do
local gridRow = {}
for col = 0, 9 do
-- draw a diamond shaped tile
local vertices = { 0,-16, -64,16, 0,48, 64,16 }
-- MY EDITED VERTICES { 0,-37.25, -128,37.25, 0,111.75, 128,37.25 }
local tile = display.newPolygon(group, 0, 0, vertices )
-- outline the tile and make it transparent
tile.strokeWidth = 1
tile:setStrokeColor( 0, 1, 1 )
tile.alpha = .4
local tileWidth = 256
local tileHeight = 149
-- set the tile's x and y coordinates
local x = col * tileHeight
local y = row * tileHeight
tile.x = (x - y)
tile.y = ((tileHeight/2) + ((x + y)/2))
-- make a tile walkable
gridRow[col] = 0
end
-- add gridRow table to the map table
j_map[row] = gridRow
end
end
As you can see in the screenshots the tiles kind of veer off the side of the map. If anyone knows how to fix it or needs more info on the information let me know!

Answer 1

Try code:
for row = 0, 16 do
local gridRow = {}
for col = 0, 9 do
-- draw a diamond shaped tile
--local vertices = { 0,-16, -64,16, 0,48, 64,16 }
-- MY EDITED VERTICES
local vertices = { 0,-37.25, -128,37.25, 0,111.75, 128,37.25 }
local tile = display.newPolygon( group, 0, 0, vertices )
-- outline the tile and make it transparent
tile.strokeWidth = 1
tile:setStrokeColor( 0, 1, 1 )
tile.alpha = .4
local tileWidth = 256
local tileHeight = 149
tile.x = -(row - col) * tileWidth * 0.5
tile.y = (row + col) * tileHeight * 0.5
-- make a tile walkable
gridRow[col] = 0
end
-- add gridRow table to the map table
--j_map[row] = gridRow
end
I get formula for xand y position of tile from Isometric Tiles Math. Good luck:)