 # Distorting X-axis on a barchart

Hello,

I have a simple bar-chart seen at http://img40.imageshack.us/img40/4889/barchart.png

What is the way to plot each bar equally spaced apart from eachother? Any simple way without defining custom ticks or manipulating the data?

Homework season has just started here. Lots of matplotting to do…

Thanks.

···

Gökhan

See the resulting image at http://img9.imageshack.us/img9/145/barchart2.png

I am thinking a keyword like “spacing” could be added to the bar(). If it is set true then an approach similar shown in the 2nd version might followed to equally space the bars instead of linear or log scaling.

Any other ideas or a hidden keyword to achieve the same plotting?

The code to produce both figures:

import numpy as np
import matplotlib.pyplot as plt

diameters, numbers = np.loadtxt(‘lab1-data’, dtype=‘int8’, skiprows=1).T

# 1st version --with linear spacing

width = 1.0
plt.bar(diameters, numbers, width=width, align=‘edge’)
plt.axis(xmin=diameters.min()-2, xmax=diameters.max()+2)
plt.xlabel(“Diameter (mm)”, fontsize=16)

plt.ylabel(“Number of washers (#)”, fontsize=16)
plt.xticks(diameters+width/2, diameters)

plt.figure()

# 2nd version --equal spacing

zipped = zip(diameters, numbers)
zipped.sort()

# Unzipping

diameters, numbers = zip(*zipped)

width = 0.4
plt.bar(range(len(diameters)), numbers, width=width, align=‘edge’)
plt.xlabel(“Diameter (mm)”, fontsize=16)
plt.ylabel(“Number of washers (#)”, fontsize=16)

plt.xticks(np.arange(len(diameters))+width/2, diameters)
plt.axis(xmin=-width/2, xmax=len(diameters)-width)

plt.show()

#Data

Diameter(mm) Number
11 7
7 44
10 24

51 1
38 2
35 3
21 12
28 16
12 8
16 8

···

On Thu, Sep 10, 2009 at 2:29 PM, Gökhan Sever <gokhansever@…287…> wrote:

Hello,

I have a simple bar-chart seen at http://img40.imageshack.us/img40/4889/barchart.png

What is the way to plot each bar equally spaced apart from eachother? Any simple way without defining custom ticks or manipulating the data?

Homework season has just started here. Lots of matplotting to do…

Thanks.

Gökhan

Gökhan