I am using QGIS Essen on Windows 10. I have a data set (.txt file) that contains latitude, longitude, and black carbon (BC) values. I can style the layer using the values of BC - graduated style, color ramp. As such: enter image description here

However, I would like to have the colors in log scale so I can still distinguish between the different low values (yellow dots). As you can see on the right side, all is just yellow. Is there a way to do this?

Update: I tried again the field calculator approach and got a nice plot. However, I would like the color ramp "logged" and not the values (please let me know if this makes sense). I'm trying to achieve something like this that I have done in Igor (but the graphics is better in QGIS): enter image description here

As you can see, the color scale is also logged. Is this possible in QGIS?

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    Welcome to GIS:SE @honeyace4! You could use the Field Calculator to create a new field using a log() expression with values from your "BC" field and then style the layer using this field. – Joseph Oct 5 '16 at 14:02
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    What style are you using now? If you use natural breaks (jenks) it should spread out many close values into more categories. – HDunn Oct 5 '16 at 14:07
  • @Joseph - I tried using the Field Calculator but it is giving me weird results. Maybe I wasn't using it correctly. – honeyace4 Oct 5 '16 at 14:23
  • @HDunn - I have actually tried playing with all the styles. The natural breaks option spread out the vertical line nicely, but not the yellow parts on the left side. – honeyace4 Oct 5 '16 at 14:24
  • If you want help troubleshooting your efforts using the Field Calculator, edit your post to include what formulas you've tried. – csk Feb 13 '18 at 17:58

You can do that easily. Go to properties of the layer, select "graduated" style and write a function like "log10("YOURATTRIBUTE")". Then classify you values.

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