Logarithmic scale with minimum axis value renders incorrectly

[mleinart]

Imported from https://bugs.launchpad.net/bugs/1092568

Reported by	campbell-stephenson
Date Created	Dec 20, 2012

Hi,

I am having a problem with version 0.9.10 of Graphite when applying a logarithmic scale (base 10) on the y axis and specifying a minimum value of 1 to the axis.

The series data has a value of about 42k and it renders correctly without the scale or the minimum value.

If I apply a minimum value of zero to the y-axis it renders correctly, but if I specify a minimum value of 1 Graphite chooses a maximum value of 40k so the series it not visible. I'm not too bothered about this but thought it was worth mentioning.

If I apply a logarithmic scale (base 10) on the y axis without a minimum set the series renders correctly but if I specify a minimum value of 1 the series is rendered below the 10k line which is incorrect.

Any help would be greatly appreciated,
Campbell

[mleinart]

Comment by campbell-stephenson on Dec 20, 2012:

[mleinart]

Comment by jakabov-launchpad on Jan 15, 2013:

This issue crops up even without without a y-axis minimum:

To reproduce: specify these params to the render api: &target=removeBelowValue(sinFunction("1000*sin(x)",1000),1)&logBase=10

Expected output: a graph with maximum value rendered at 1000

Actual output: maximum value is rendered between 100 and 1000 on the y axis.

It appears that the labels on the y-axis are not aligned correctly with the grid and the rendered data.

[jdanbrown]

Thanks @ralphm! This bug has been bothering me for a while on 0.9.10. (Merged into my own fork.)