change "elevation scale" to adjust colors to match range

I am trying to display wind speed data - the default data set covers a wide range of data (4 to 16) but the area I am looking at is much narrowower. I would like to crop the display limits and then remap the color bar to fit this smaller range. 

Answers

  • sorry forgot to add sample picture - trying to remap colorbar to fit range 6.5-10
  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,681
    You can set the range for the Elevation Legend by right-clicking on the legend and choosing Set Elevation Legend Range...  On the resulting Specify Legend Range dialog, check to Custom option and type in the minimum and maximum values you want to use.
  • i can change the values but the color map does not rescale. i would like to reset and then show a larger color variation for smaller number range if that makes sense. 
    currently red to blue color map is associated with 5-15 m/s
    i want red to blue spread over 5-8

    thanks in advance. 

  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,681
    edited January 2016
    i can change the values but the color map does not rescale. i would like to reset and then show a larger color variation for smaller number range if that makes sense. 
    currently red to blue color map is associated with 5-15 m/s
    i want red to blue spread over 5-8


    Have you tried creating a custom shader?  That would allow you to specify a range of values and the colors to use for the end points, with interpolation for values that are in between.
  • saskalisaskali Posts: 1
    bmg_bob said:
    i can change the values but the color map does not rescale. i would like to reset and then show a larger color variation for smaller number range if that makes sense. 
    currently red to blue color map is associated with 5-15 m/s
    i want red to blue spread over 5-8


    Have you tried creating a custom shader?  That would allow you to specify a range of values and the colors to use for the end points, with interpolation for values that are in between.
    I am having the same issue but with elevation. I do not want to crop the elevation data to my area of interest, because I do need the higher elevations as well, but my area of interest is pretty much within a 10 m range (while the overat data set is more like a 100 m range. I set up a custom shader, but how do I apply to to a data set already loaded? I have looked in the manual and have not found an answer. I would hope this must be straightforward and feel silly for not being able to figure out how to 'turn on' the custom shader?
  • bmg_bobbmg_bob Global Mapper Programmer Posts: 1,681
    saskali said:
    I set up a custom shader, but how do I apply to to a data set already loaded?
    In the toolbar, there is a drop-down list that contains all of the defined shaders, both built-in and custom.  You should be able to select your shader from that list.

    Cheers,
    Bob
  • JSOJSO Posts: 6
    bmg_bob said:
    i can change the values but the color map does not rescale. i would like to reset and then show a larger color variation for smaller number range if that makes sense. 
    currently red to blue color map is associated with 5-15 m/s
    i want red to blue spread over 5-8


    Have you tried creating a custom shader?  That would allow you to specify a range of values and the colors to use for the end points, with interpolation for values that are in between.
    Creating a custom shader every time you want to set the elevation range is inconvenient, especially when there is already an option when creating custom shaders to scale the shader to loaded elevation values. That should be an option on the default shaders.
  • MykleMykle Global Mapper User Posts: 378Trusted User
    Bob, looks like the desired option would be similar to the options available when exporting data, whether to scale to the entire loaded data set, or scale to the data set that is visible, or scale to the values within a selected object. 

    It may be useful to be able to choose the layers to be used for scaling, whether for one layer or for the layers currently visible. 

    I can envision having detailed data for a small area (like LIDAR) and wide area data for the extents of the project (like SRTM) with layers set to show the detail where available, and I would want to scale to the visible data from these two layers.  (geophysical gravity data is adjusted for terrain by using detailed elevation data for the survey area and wide area coverage out to 100km)

    Having the kitchen sink would be useful as well.

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