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Distance variation in Grid feature using MapInfo Professional


I'm using MapInfo Professional version 10.5 for Digitization. We can create Grids from "Create Grid" feature of MapInfo. From Grid Maker(version 1.4) window i'm selecting

Object Types: Closed Regions

Object Styles: Regions

Extents: (Automatically loads value), unselected Round Extents checkbox.

Spacing Between lines: eg: 2236.06 selected meter option.

Smoothness: 0

then press ok for getting Grid.

I can view Grids on the map.

But, When i'm trying to measure length of each grid using measure tool(Ruler) in mapinfo, it is showing zig zag values. eg: one grid length will be 2240 and other will be 2230 like that.. How can i solve this problem .. Please share your ideas here ..

Thank you..

Ramesh T.R.


Solution

  • This may be due to the way that MapInfo stores coordinates. If the bounds of your TAB file are very large (which I'm assuming they are as your grid size is a couple of kilometers) then the below may be the root cause.

    MapInfo slices the area you tell it you're interested in (the bounds of the file) into a grid and then stores coordinates as integers (see here: http://www.mapsbydesign.co.uk/pdfs/boundsclause.pdf for more detail). The means that the bigger the area of interest, the less accurate your coordinates are. If your grid size ended up being 10 meters, then you'd expect to see something like what you describe above, where the real-world coordinates end up getting snapped to the closest grid point.