How can I change the ticklabels of numeric decimal data (say between 0 and 1) to be "0", ".1", ".2" rather than "0.0", "0.1", "0.2" in matplotlib? For example,
hist(rand(100))
xticks([0, .2, .4, .6, .8])
will format the labels as "0.0", "0.2", etc. I know that this gets rid of the leading "0" from "0.0" and the trailing "0" on "1.0":
from matplotlib.ticker import FormatStrFormatter
majorFormatter = FormatStrFormatter('%g')
myaxis.xaxis.set_major_formatter(majorFormatter)
That's a good start, but I also want to get rid of the "0" prefix on "0.2" and "0.4", etc. How can this be done?
Although I am not sure it is the best way, you can use a matplotlib.ticker.FuncFormatter
to do this. For example, define the following function.
def my_formatter(x, pos):"""Format 1 as 1, 0 as 0, and all values whose absolute values is between0 and 1 without the leading "0." (e.g., 0.7 is formatted as .7 and -0.4 isformatted as -.4)."""val_str = '{:g}'.format(x)if np.abs(x) > 0 and np.abs(x) < 1:return val_str.replace("0", "", 1)else:return val_str
Now, you can use majorFormatter = FuncFormatter(my_formatter)
to replace the majorFormatter
in the question.
Complete example
Let's look at a complete example.
from matplotlib import pyplot as plt
from matplotlib.ticker import FuncFormatter
import numpy as npdef my_formatter(x, pos):"""Format 1 as 1, 0 as 0, and all values whose absolute values is between0 and 1 without the leading "0." (e.g., 0.7 is formatted as .7 and -0.4 isformatted as -.4)."""val_str = '{:g}'.format(x)if np.abs(x) > 0 and np.abs(x) < 1:return val_str.replace("0", "", 1)else:return val_str# Generate some data.
np.random.seed(1) # So you can reproduce these results.
vals = np.random.rand((1000))# Set up the formatter.
major_formatter = FuncFormatter(my_formatter)plt.hist(vals, bins=100)
ax = plt.subplot(111)
ax.xaxis.set_major_formatter(major_formatter)
plt.show()
Running this code generates the following histogram.
Notice the tick labels satisfy the conditions requested in the question.