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Pro Advanced automatically changing appearance of MIG files

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  • 1.  Pro Advanced automatically changing appearance of MIG files

    Posted 08-14-2019 20:52
    I've been advised that when MapInfo Pro has the Advanced licence enabled, it automatically alters the appearance of a MIG file (i.e. the old grid format) when opened. Specifically: it creates a GHX file, applies a default colour ramp, and enables hill shading.

    The colour can subsequently be altered using 'Set Map... Layer... Reflect...' MapBasic statement, however setting 'Relief Off' has no effect on the hill shading.

    I've tried using standard MapInfo Pro v17.0.3 and it operates OK, so I'm pretty sure it's the Advanced licence which is affecting the MIG files. We've tried switching off 'Enable Hill Shade' under Pro -> Options -> MapInfo Pro Raster -> Preferences, but it didn't solve it.

    Is there a way to display the MIG file using its native appearance settings? Or perhaps can a GHX file be written which sets the desired styles?

    Thanks, Tim


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    Timothy Mashford
    Melbourne, Australia
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  • 2.  RE: Pro Advanced automatically changing appearance of MIG files
    Best Answer

    Pitney Bowes
    Posted 08-15-2019 21:55
    MapInfo Pro Advanced (up to and including version 17.04) does not load MIG files. I don't think the GHX file (or the rendering information it contains) is used in any way. MIG files get loaded by the MapInfo grid handlers which do not interact with the Advanced raster handler.

    My best guess is that you have Datamine Discover installed, or some product derived from Discover like Crime Profiler or Engage3D. This could have an impact because I believe MIG handlers were shipped with those products - possibly both raster and grid handlers.

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    Sam Roberts
    Engineer, MapInfo Pro Advanced (Raster)
    Australia
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  • 3.  RE: Pro Advanced automatically changing appearance of MIG files

    Posted 08-16-2019 00:23
    Thanks Sam, yes I believe Discover is installed on the PC so that must be causing the issue.

    I'm not sure of a solution in that case, maybe I can write the output surface as an ascii grid, if it will then allow for colours to be set and hill shading switched off.

    (Or are there any other suggested ways to write a grid cell by cell, without requiring the Pro Advanced licence?)

    Regards,

    Tim

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    Timothy Mashford
    Melbourne, Australia
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  • 4.  RE: Pro Advanced automatically changing appearance of MIG files

    Pitney Bowes
    Posted 28 days ago
    If you want a simple grid format that you can write yourself then I suggest Arc ASCII, Arc Float, BIL or ERMapper ERS.

    Arc ASCII is the simplest but also the worst. It is ASCII with a header section and then all the cell data following. Fine for small rasters.
    Arc Float is better. It has the same ASCII header (in a separate file) and then a simple binary array in another file. Better for larger rasters.
    BIL is very similar to Arc Float and if you want to write out data in something other than 4-byte real, you can use this.
    ERS is very similar to BIL but the header is a little more complicated to write.

    MIG combines the raster data with information on how to render it into one file. This is a bad thing (in principle) because these things ought to be kept separate so you can control them independently. (Of course, TAB files do the same thing...) Anyway, it is not something we support with much conviction in the raster code. For example, Vertical Mapper files also contain rendering information and we kind of load it, but then kind of ignore it.

    If you write an Arc Float raster and then want it rendered in a particular way then you need to write a GHX file with the rendering information in it. Note that the GHX file has a particular file naming convention (RasterName_RasterExtension.GHX). The best thing to do is to make a raster and color it the way you want and then use that GHX file as a template. The GHX file does not name the source raster so you can use the same file for all the rasters you produce. If you want some more detailed information about any of this just send me an email (sam.roberts@pb.com).

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    Sam Roberts
    Engineer, MapInfo Pro Advanced (Raster)
    Australia
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  • 5.  RE: Pro Advanced automatically changing appearance of MIG files

    Posted 28 days ago
    Thanks Sam, I have it working with the arc ascii format.

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    Timothy Mashford
    Melbourne, Australia
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