Re: [Visualpython-users] Clarifying question regarding semi-log plots

[Bruce S. <Bru...@nc...>]

I'm assuming that what concerns you is that you don't want the x axis 
labeled 0, 2, 4 but rather 1, 100, 1e4. visual.graph doesn't provide 
this capability. Your solution, to use and label the x axis in terms of 
the log10 of the quantity of interest, is the best you can do, and is 
indeed a semilog plot of the data.

However, notice that visual.graph is simply a Python program, so you 
could make a copy of it, modify it, and import it instead of 
visual.graph. The revised version might be of general interest.

Bruce Sherwood

Gabor Kalman wrote:
> In my earlier (9/11/08) "submit" I asked:
>     "How can one "fool" Vpython  to display y=f(log10(x))  as a semi-log 
> plot?"
>  
> To clarify:
>     How can I change the "tick-marks" to a log scale?
>  
> see sample program below:
>  
> ************************
>  
> from visual import *
> from visual.graph import *
>  
> 
> graph1=gdisplay(x=0,y=0, 
> width=400,height=300,title="semilog",xtitle="f=10^x",
>                 ytitle="y",xmax=4,xmin=1,ymax=500,ymin=0,
>                 foreground=color.black,background=color.white)
> plot1 = gvbars(delta=0.5, color=color.green)
>  
> x=[10,100,1000]
> y=[400,200,100]
>  
> for i in range(0,3):
>     plot1.plot(pos=(log10(x[i]),y[i]))