Myujth

Is there any way to set the y coordinate(s) of the bars bases in gnuplot bar charts as the bottom option in matplotlib?

For example, suppose I have the following data:

0.5 0.2 0.3 0.1 0.2 0.1
0.6 0.1 0.2 0.1 0.2 0.0
0.4 0.2 0.1 0.1 0.5 0.3

In matplotlib I can do the following procedure:

import matplotlib.pyplot as plt
import numpy as np

a = np.loadtxt('sample.dat', usecols=[0], dtype=float).tolist()
a1 = np.loadtxt('sample.dat', usecols=[1], dtype=float).tolist()
b = np.loadtxt('sample.dat', usecols=[2], dtype=float).tolist()
b1 = np.loadtxt('sample.dat', usecols=[3], dtype=float).tolist()
c = np.loadtxt('sample.dat', usecols=[4], dtype=float).tolist()
c1 = np.loadtxt('sample.dat', usecols=[5], dtype=float).tolist()

x_pos = np.arange(len(a))
plt.bar(x_pos,a, align='center', color='green');
plt.bar(x_pos,b, align='center', bottom=a, color='red');
plt.bar(x_pos,c, align='center', bottom=np.add(a, b).tolist(), color='orange');
plt.bar(x_pos,a1, align='center', bottom=None, color='black');
plt.bar(x_pos,b1, align='center', bottom=a, color='blue');
plt.bar(x_pos,c1, align='center', bottom=np.add(a, b).tolist(), color='gray');
plt.xticks(np.arange(0, len(a)));

Getting the following graph:

Bar chart

There is a gnuplot plot style that allows you to specify both the top and bottom of each box (and the left and right also). It is

plot FOO using (x):(y):(xlow):(xhigh):(ylow):(yhigh) with boxxy

However there is a much better was of generating stacked histogram plots such as the one you show.

set style data histogram
set style histogram columnstacked
set style fill solid border lc "black"
plot for [col=4:7] FOO using col title sprintf("Col %d",col)