id summary reporter owner description type status priority milestone component version resolution keywords cc must_fix platform platform_version status_info 1497 colormap edge case handling wrong for negative valued rasters Barryrowlingson ersts "I have a single-band floating-point raster. It's 20x20 so I can see the cells. From layer properties choose 'Colormap', on the Colormap tab use Discrete Color Interpolation, in generate new color map section choose 4 entries, equal interval color map, hit Classify, hit apply. The colormap values define inclusive upper values. For a positive-valued raster I get three areas of color and a single cell coloured in the shade of the smallest value, since that's the only cell which has the minimum value. But for a negative-valued raster I get three areas of colour and a blank cell at the highest value. Let's explain with some colormaps. My positive raster has a range of 0.563 to 8.38, and I get this colormap: 0.563: blue 3.169: yellow 5.775: green 8.38 : red I see one blue cell (at the single pixel with the minimum value) and some yellow, green and red cells. All cells are shaded. With my negative raster (which is just (* -1 pos) in RasterLang) I get the following colormap: -8.38 : blue -5.775: yellow -3.169: green -0.563: red and I see one transparent cell, no blue cells, and some yellow, green and red cells. The transparent cell is at the -0.563 value location. See attachment. If things were symmetric with the positive raster, it should be red, but it doesn't get shaded. As it is, it seems that a positive floating point raster will always have cells of the single max colour done in one shade, and a negative fp raster will always have cells of the minimum colour set transparent... Also note the 'Exact' interpolation doesn't match any cells - I thought it might find equality with the min and max cells, but doesn't. Probably only useful for integer rasters. " bug closed major: does not work as expected Rasters Trunk fixed No Linux 0