log(x) axis with negative powers of ten

[Guillaume William Bres]

Hi,

I'm building an application where I need to monitor frequency domain data and we use the log(x) feature all the time.

My x (frequency) axis ranges from 1e6 (MHz) down to 1e-3 (mHz) and it seems like pyqtgraph is not capable of dealing with 1e^n as long as N<0, by "not dealing", I mean I am no longer getting proper ticks, lines are not displayed and displaying is messed up (dHz & mHz are not even displayed).

Is there a way I can work around this by creating a custom axis item?

I always build PyQtGraph from the "master" branch which is fairly outdated, should I switch to "develop"?

[Guillaume William Bres]

so it turned out the log(x) display was somehow corrupted by my xRange(xMin,xMax) values.

My x values range from 0 to 1e7 (0 to 10MHz). My actual data ranges from 1e-3 (1mHz) to 1e7 (10MHz). I previously set xRange(1e-9 to 1e7) to avoid log(0) @xMin and so the user can slightly scroll below the smallest x value.

In this setup I am no longer getting nicely logarithmically spaced vertical lines, 1e^n where n<0 are not displayed. Then modified xRange to (-100,1e7) and now I am getting proper vertical lines.

So xRange(-100,1e7) is a solution to get proper vertical lines, but the overall UI is no longer super nice because my values never reach x<0, and the user can actually scroll down to -100(whatever xMin value I set)

don't know what's happening with axisItems or whatever class is used in all of that

[Luke Campagnola]

Can you post a code example? Here's my simple test:

>>> import pyqtgraph as pg
>>> import numpy as np
>>> plt = pg.plot(10.0**np.arange(-3,8), np.arange(-3,8), symbol='o')                                                                                                                                                                     
>>> plt.setLogMode(x=True, y=False)

And the output looks correct to me:

--
You received this message because you are subscribed to the Google Groups "pyqtgraph" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pyqtgraph+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pyqtgraph/f1764361-15a6-4d91-a4de-59ac31916a0c%40googlegroups.com.

For more options, visit https://groups.google.com/d/optout.