I'm attempting to create a scatter plot bounded by histograms of the data to the left and bottom of the scatter plot. I have been following this example (where the plot is bounded to the top and right):
http://matplotlib.sourceforge.net/examples/pylab_examples/scatter_hist.html
I have successfully changed the margins and sizes to get the histograms where I want them, but I'm not sure how to tell mpl where to put the xlabel and ylabel. For example, using (where now axHistx and axHisty are modified to be left of/below the scatter):
axScatter = axes(scat_area)
axHistx = axes(hist_area_x)
axHisty = axes(hist_area_y)
...
xlabel('this is the x axis')
ylabel('this is the y axis')
Will place the xlabel below the histogram on the left (axHisty). I want it centered under the histogram on the bottom. I cannot use axHistx.xlabel() since axes objects do not have that attribute. (I am happy with where the ylabel has eneded up, though)
This should work:
axHisty.set_xlabel("this is the x axis")
Related
I need the plot legend to appear side-by-side to the plot axes, i.e. outside of the axes and non-overlapping.
The width of the axes and the legend should adjust "automatically" so that they both fill the figure w/o them to overlap or the legend to be cut, even when using tight layout. The legend should occupy a minor portion of the figure (let's say max to 1/3 of figure width so that the remaining 2/3 are dedicated to the actual plot).
Eventually, the font of the legend entries can automatically reduce to meet the requirements.
I've read a number of answers regarding legend and bbox_to_anchor in matplotlib with no luck, among which:
how to put the legend out of the plot
moving matplotlib legend outside of the axis makes it cutoff by the figure box
I tried by creating a dedicated axes in which to put the legend so that plt.tight_layout() would do its job properly but then the legend only takes a minor portion of the dedicated axes, with the result that a lot of space is wasted. Or if there isn't enough space (the figure is too small), the legend overlaps the first axes anyway.
import matplotlib.pyplot as plt
import numpy as np
# generate some data
x = np.arange(1, 100)
# create 2 side-by-side axes
fig, ax = plt.subplots(1,2)
# create a plot with a long legend
for ii in range(20):
ax[0].plot(x, x**2, label='20201110_120000')
ax[0].plot(x, x, label='20201104_110000')
# grab handles and labels from the first ax and pass it to the second
hl = ax[0].get_legend_handles_labels()
leg = ax[1].legend(*hl, ncol=2)
plt.tight_layout()
I'm open to use a package different from matplotlib.
Instead of trying to plot the legend in a separate axis, you can pass loc to legend:
# create 2 side-by-side axes
fig, ax = plt.subplots(figsize=(10,6))
# create a plot with a long legend
for ii in range(20):
ax.plot(x, x**2, label='20201110_120000')
ax.plot(x, x, label='20201104_110000')
# grab handles and labels from the first ax and pass it to the second
ax.legend(ncol=2, loc=[1,0])
plt.tight_layout()
Output:
I have this weird thing with the scale of the axis showing out of the figure like:
And what I want to have:
How can I move the scale to the other side of the axis?
x=range(len(ticks))
plt.plot(x,phase1,'r^-',label='$\Delta \phi(U1,I1)$')
plt.plot(x,phase2,'go-',label='$\Delta \phi(U2,I2)$')
plt.plot(x,phase3,'b*-',label='$\Delta \phi(U3,I3)$')
plt.xticks(x,ticks,rotation=45)
plt.xlabel('Messung')
plt.ylabel('$\Delta \phi [^\circ]$')
plt.legend()
plt.show()
The tick_params of your axis can be used to control axes label and ticks location. Set direction to in so that they point into the graph.
And here is a great example if you want different y-axis ranges and colours too.
from matplotlib import pyplot as plt
fig = plt.figure()
ax = fig.add_subplot(111)
ax.tick_params(direction='in', length=6, width=2, colors='r', right=True, labelright='on')
plt.show()
You can use plt.tick_params() to adjust the behaviour of the ticks, documentation can be found here.
For your example you want the ticks to appear inside the figure. Therefore add
plt.tick_params(direction="in")
to your code. Example:
x=range(len(ticks))
plt.plot(x,phase1,'r^-',label='$\Delta \phi(U1,I1)$')
plt.plot(x,phase2,'go-',label='$\Delta \phi(U2,I2)$')
plt.plot(x,phase3,'b*-',label='$\Delta \phi(U3,I3)$')
plt.xticks(x,ticks,rotation=45)
plt.xlabel('Messung')
plt.ylabel('$\Delta \phi [^\circ]$')
plt.legend()
plt.tick_params(direction="in") # Set ticks inside the figure
plt.show()
You can get the ticks to appear on the top and right side of the figure too as shown in your second screenshot by adding:
plt.tick_params(direction="in",top="on",right="on")
If you wanted to make all figures in your Python script have this behaviour then you can add the following at the top of your script (this might be of interest):
import matplotlib
matplotlib.rcParams['xtick.direction'] = "in"
matplotlib.rcParams['ytick.direction'] = "in"
This will save you having to call plt.tick_params() for each figure, which is helpful if you generate lots of figures.
I am new to matplotlib and trying to create and save plots from pandas dataframes via a loop. Each plot should have an identical x-axis, but different y-axis lengths and labels. I have no problem creating and saving the plots with different y-axis lengths and labels, but when I create the plots, matplotlib rescales the x-axis depending on how much space is needed for the y-axis labels on the left side of the figure.
These figures are for a technical report. I plan to place one on each page of the report and I would like to have all of the x-axes take up the same amount of space on the page.
Here is an MSPaint version of what I'm getting and what I'd like to get.
Hopefully this is enough code to help. I'm sure there are lots of non-optimal parts of this.
import pandas as pd
import matplotlib.pyplot as plt
import pylab as pl
from matplotlib import collections as mc
from matplotlib.lines import Line2D
import seaborn as sns
# elements for x-axis
start = -1600
end = 2001
interval = 200 # x-axis tick interval
xticks = [x for x in range(start, end, interval)] # create x ticks
# items needed for legend construction
lw_bins = [0,10,25,50,75,90,100] # bins for line width
lw_labels = [3,6,9,12,15,18] # line widths
def make_proxy(zvalue, scalar_mappable, **kwargs):
color = 'black'
return Line2D([0, 1], [0, 1], color=color, solid_capstyle='butt', **kwargs)
# generic image ID
img_path = r'C:\\Users\\user\\chart'
img_ID = 0
for line_subset in data:
# create line collection for this run through loop
lc = mc.LineCollection(line_subset)
# create plot and set properties
sns.set(style="ticks")
sns.set_context("notebook")
fig, ax = pl.subplots(figsize=(16, len(line_subset)*0.5)) # I want the height of the figure to change based on number of labels on y-axis
# Figure width should stay the same
ax.add_collection(lc)
ax.set_xlim(left=start, right=end)
ax.set_xticks(xticks)
ax.set_ylim(0, len(line_subset)+1)
ax.margins(0.05)
sns.despine(left=True)
ax.xaxis.set_ticks_position('bottom')
ax.set_yticks(line_subset['order'])
ax.set_yticklabels(line_subset['ylabel'])
ax.tick_params(axis='y', length=0)
# legend
proxies = [make_proxy(item, lc, linewidth=item) for item in lw_labels]
ax.legend(proxies, ['0-10%', '10-25%', '25-50%', '50-75%', '75-90%', '90-100%'], bbox_to_anchor=(1.05, 1.0),
loc=2, ncol=2, labelspacing=1.25, handlelength=4.0, handletextpad=0.5, markerfirst=False,
columnspacing=1.0)
# title
ax.text(0, len(line_subset)+2, s=str(img_ID), fontsize=20)
# save as .png images
plt.savefig(r'C:\\Users\\user\\Desktop\\chart' + str(img_ID) + '.png', dpi=300, bbox_inches='tight')
Unless you use an axes of specifically defined aspect ratio (like in an imshow plot or by calling .set_aspect("equal")), the space taken by the axes should only depend on the figure size along that direction and the spacings set to the figure.
You are therefore pretty much asking for the default behaviour and the only thing that prevents you from obtaining that is that you use bbox_inches='tight' in the savefig command.
bbox_inches='tight' will change the figure size! So don't use it and the axes will remain constant in size. `
Your figure size, defined like figsize=(16, len(line_subset)*0.5) seems to make sense according to what I understand from the question. So what remains is to make sure the axes inside the figure are the size you want them to be. You can do that by manually placing it using fig.add_axes
fig.add_axes([left, bottom, width, height])
where left, bottom, width, height are in figure coordinates ranging from 0 to 1. Or, you can adjust the spacings outside the subplot using subplots_adjust
plt.subplots_adjust(left, bottom, right, top)
To get matching x axis for the subplots (same x axis length for each subplot) , you need to share the x axis between subplots.
See the example here https://matplotlib.org/examples/pylab_examples/shared_axis_demo.html
I am trying to rotate the title of the Y axis so it is horizontal. I do not want the tick labels horizontal just the title of the Y axis. I have to use subplots as I am making multiple plots at once. Here is the below script in which I have tried to rotate the Y axis title.
import matplotlib.pyplot as plt
import sys
fig, ax = plt.subplots()
ax.set_title(r'$\alpha$ > \beta_i$', fontsize=20)
ax.set(xlabel='meters $10^1$', ylabel=r'Hertz $(\frac{1}{s})$')
ax.set(xlabel=r's(t) = \mathcal(A)\/\sin(2 \omega t)', ylabel=r'Hertz $(\frac{1}{s})$')
ax.set(ylabel="North $\uparrow$",fontsize=9,rotate=90)
plt.show()
When I run it I get an error:
TypeError: There is no AxesSubplot property "rotate"
How can I tweak this program so that the Y axis is rotating horizontally?
By using ax.set you are attempting to set properties of the axes rather than properties of the ylabel text object.
Rather than using ax.set you can instead use xlabel and ylabel to create the x and y labels and pass in kwargs to modify their appearance. Also the property name is rotation rather than rotate. Also you'll want to set the rotation to 0 as the default is 90 which is why it's rotated in the first place.
plt.title(r'$\alpha > \beta_i$', fontsize=20)
plt.xlabel(r'meters $10^1$', fontsize=9)
plt.ylabel("North $\uparrow$", fontsize=9, rotation=0)
I'm writing a pythonic script for a coastal engineering application which should output, amongst other things, a figure with two subplots.
The problem is that I would like to shade a section of both subplots using plt.axvspan() but for some reason it only shades one of them.
Please find below an excerpt of the section of the code where I set up the plots as well as the figure that it's currently outputting (link after code).
Thanks for your help, and sorry if this is a rookie question (but it just happens that I am indeed a rookie in Python... and programming in general) but I couldn't find an answer for this anywhere else.
Feel free to add any comments to the code.
# PLOTTING
# now we generate a figure with the bathymetry vs required m50 and another figure with bathy vs Hs
#1. Generate plots
fig = plt.figure() # Generate Figure
ax = fig.add_subplot(211) # add the first plot to the figure.
depth = ax.plot(results[:,0],results[:,1]*-1,label="Depth [mDMD]") #plot the first set of data onto the first set of axis.
ax2 = ax.twinx() # generate a secondary vertical axis with the same horizontal axis as the first
m50 = ax2.plot(results[:,0],results[:,6],"r",label="M50 [kg]") # plot the second set of data onto the second vertical axis
ax3 = fig.add_subplot(212) # generate the second subplot
hs = ax3.plot(results[:,0],results[:,2],"g",label="Hs(m)")
#Now we want to find where breaking starts to occur so we shade it on the plot.
xBreakingDistance = results[numpy.argmax(breakingIndex),0]
# and now we plot a box from the origin to the depth of breaking.
plt.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1) # this box is called a span in matplotlib (also works for axhspan)
# and then we write BREAKING ZONE in the box we just created
yLimits = ax.get_ylim() # first we get the range of y being plotted
yMiddle = (float(yLimits[1])-float(yLimits[0])) / 2 + yLimits[0] # then we calculate the middle value in y (to center the text)
xMiddle = xBreakingDistance / 2 # and then the middle value in x (to center the text)
#now we write BREAKING ZONE in the center of the box.
ax.text(xMiddle,yMiddle,"BREAKING ZONE",fontweight="bold",rotation=90,verticalalignment="center",horizontalalignment="center")
#FIGURE FORMATTING
ax.set_xlabel("Distance [m]") # define x label
ax.set_ylabel("Depth [mDMD]") # define y label on the first vertical axis (ax)
ax2.set_ylabel("M50 [kg]") # define y label on the second vertical axis (ax2)
ax.grid() # show grid
ax3.set_xlabel("Distance[m]") #define x label
ax3.set_ylabel("Hs[m]") # define y label
ax3.grid()
plt.tight_layout() # minimize subplot labels overlapping
# generating a label on a plot with 2 vertical axis is not very intuitive. Normally we would just write ax.label(loc=0)
combined_plots = depth+m50 #first we need to combine the plots in a vector
combined_labels = [i.get_label() for i in combined_plots] # and then we combine the labels
ax.legend(combined_plots,combined_labels,loc=0) # and finally we plot the combined_labels of the combined_plots
plt.savefig("Required M50(kg) along the trench.png",dpi=1000)
plt.close(fig)
Output Figure:
By just calling plt.axvspan, you are telling matplotlib to create the axvspan on the currently active axes (i.e. in this case, the last one you created, ax3)
You need to plot the axvspan on both of the axes you would like for it to appear on. In this case, ax and ax3.
So, you could do:
ax.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1)
ax3.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1)
or in one line:
[this_ax.axvspan(0,xBreakingDistance,facecolor="b",alpha=0.1) for this_ax in [ax,ax3]]
It's difficult to analyze your code and not being able to reproduce it. I advise you to build a minimal example. In any case notice that you are calling "plt.axvspan(" which is general call to the library.
You need to specifically state that you want this in both "ax" and "ax2" (i think).
Also if you need more control consider using Patches (I don't know axvspan):
import matplotlib.pyplot as plt
import matplotlib.patches as patches
fig1 = plt.figure()
ax1 = fig1.add_subplot(111, aspect='equal')
ax1.add_patch(
patches.Rectangle(
(0.1, 0.1), # (x,y)
0.5, # width
0.5, # height
)
)
fig1.savefig('rect1.png', dpi=90, bbox_inches='tight')
See that call to "ax1" in the example? Just make something similar to yours. Or just add axvspan to each of your plots.