Re: [Matplotlib-users] x axis non-uniform labeling (KURT PETERS)

[Sterling S. <sm...@fu...>]

On Oct 1, 2013, at 8:59AM, KURT PETERS wrote:

> 
> REPLY:
> ============================================================
>  
> here's what SHOULD be happening
>  
>     | 0   1   5  9 13 18 21 24 25 28
>  3 |                     x
>     |                x          x
>     |           x                    x
>     |       x                             x
> -1|_x__________________x_____
>        1    2  3   4  5    6   7   8   9  10
>  
> How can I make that happen?  Instead, MPL is autoranging the top axis.  I don't want that   I just want the actual labels to occur up there.
>  
> Kurt

Kurt,

Here is a self-contained example of what I think you are asking for:

{{{
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.ticker import FuncFormatter, MaxNLocator

simtimedata = np.array([0, 1, 5, 9, 13, 18, 21, 24, 25, 28, 31, 32, 41, 55, 56, 57])
idatanp = np.array([-1,0, 1, 2, 3, 2, 1, 0, -1, -2, -3, -2, -1, 0, -1, -2])
xdat = range(len(simtimedata))
fig = plt.figure()

ax1 = fig.add_subplot(211)
ax1.plot(xdat,idatanp)
ax1.grid(True)
ax2 = fig.add_subplot(212)
ax2.plot(xdat, idatanp.real,'k-o')
def index_to_label(i,dummy):
    if i >= 0 and i < len(simtimedata):
        return str(simtimedata[i])
    else:
        return ''

form = FuncFormatter(index_to_label)
ax2.xaxis.set_major_formatter(form)

#ax2.set_title("time domain")
ax2.grid(True)
plt.show()
}}}

You may also be interested in this question and answer on stackoverflow:
http://stackoverflow.com/questions/3918028/how-do-i-plot-multiple-x-or-y-axes-in-matplotlib

-Sterling