I have raster dataset for rainfall but it does not have an attribute table.
How can I create tabular data using the same raster file and the join back again to it?
Software used is ArcMap 10.1.
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3 Answers
You could use the Build Raster Attribute Table (Data management) tool. Note that the raster must have a single band and the pixel values must be integer type (not float or double) to have an attribute table.
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2If your data was for example to 2 decimal places then you can multiply your data by 100 to move the decimal place and then use the INT tool to convert it into an integer grid. Then you'll be able to build raster table as described above.You just got to remember to divide any output by 100 to turn it back into the original values.– HornbyddNov 8, 2014 at 20:50
I found this problem occuring mainly when handling raster data with floating point data. The straight forward approach (in the ArcMap Toolbox' sense of way):
ArcToolbox > Spatial Analyst Tools > Map Algebra > Raster Calculator
Multiply your raster by 10**X with X corresponding the maximum decimal places contained. The new raster should now be free of digits, although still being a floating pixel value raster.
ArcToolbox > Data Management Tools > Raster > Raster Dataset > Copy Raster
In the Pixel Value drop-down menu select the Pixel Type suiting your data.
Now that you have a non-float raster (and ArcMap surely loves these) create an attribute table:
ArcToolbox > Data Management Tools > Raster > Raster Properties > Build Raster Attribute Table
Open the attribute table, add a field and use Field Calculator to get your old pixel values back - by calculating "Your Value= 1 / 10**X"
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You can use Int tool to convert floating point to integer raster and after you process that, the attribute table will appear.
