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ETOPO1 Colormap File????

October 27 2011 | 2 comments
Categories: Map Data

I downloaded "ETOPO1 Colormap File" from the Mapping Center,and I followed the instructions of "Making Beautiful Maps", I can't get the map what I want, so I open "ETOPO1 Colormap File" with notepad, I just found the highest number is 20999 (it supose to be 19169?) Could anyone please tell me how can I make the map with "ETOPO1 Colormap File"! THX

Mapping Center Answer:

There is a limitation in ArcGIS 10 (this will be fixed in 10.1) that requires all values in color map files to be positive. Since ETOPO1 data also includes bathymetry, some of the elevation values are less than zero (so they are underwater). Therefore, in order to get the color map file to work, you need to make all the values in the ETOPO1 data AND the color map file positive. To do this, use the Plus tool to add 10,891 (the lowest value in the ETOPO1 data is -10,891) to the original ETOPO1 data. Then you can use the color map (the values in the color map file have already been adjusted so that they are all positive).

it's helped! posted by fei liu on Nov 2 2011 5:43AM
Thank you so much!
Glad it worked! posted by Aileen Buckley on Nov 2 2011 10:04AM
Sorry for the confusion -- glad this worked for you! And I am also glad that this problem will be fixed in version 10.1!

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