How to set specific descending x axis in matplotlib? - python

Easy question; I have 2 sets of data, approx 500 entries:
iStart, iStop, iStep = 0.2, 100, 0.2
x = list(np.arange(iStart, iStop+iStep, iStep))
y = np.random.uniform(20,25,(500,1))
plt.plot(x, y[::-1])
I want to have on the x-axis from left to right the vector x; descending. When I use there [::-1], the y values change as well.

There is a Matplotlib example for doing just this.
Edit: OP asked about adjusting x-ticks... I have made a deliberately awful example to show how this works. Passing an array into plt.xticks([100, 20, 5]) tells it which to show. Using np.arrange(start, stop, step) for example could give you an evenly spaced array.
Solution
import numpy as np
iStart, iStop, iStep = 0.2, 100, 0.2
x = list(np.arange(iStart, iStop+iStep, iStep))
y = np.random.uniform(20,25,(500,1))
fig, ax = plt.subplots(nrows = 1, ncols = 1)
ax.plot(x, y[::-1])
ax.set_xlim(np.max(x),np.min(x))
plt.xticks([100, 20, 5])
plt.show()
Output

Related

Matplotlib + pandas change xtick label frequency when using period[Q-DEC] [duplicate]

I am trying to fix how python plots my data.
Say:
x = [0,5,9,10,15]
y = [0,1,2,3,4]
matplotlib.pyplot.plot(x,y)
matplotlib.pyplot.show()
The x axis' ticks are plotted in intervals of 5. Is there a way to make it show intervals of 1?
You could explicitly set where you want to tick marks with plt.xticks:
plt.xticks(np.arange(min(x), max(x)+1, 1.0))
For example,
import numpy as np
import matplotlib.pyplot as plt
x = [0,5,9,10,15]
y = [0,1,2,3,4]
plt.plot(x,y)
plt.xticks(np.arange(min(x), max(x)+1, 1.0))
plt.show()
(np.arange was used rather than Python's range function just in case min(x) and max(x) are floats instead of ints.)
The plt.plot (or ax.plot) function will automatically set default x and y limits. If you wish to keep those limits, and just change the stepsize of the tick marks, then you could use ax.get_xlim() to discover what limits Matplotlib has already set.
start, end = ax.get_xlim()
ax.xaxis.set_ticks(np.arange(start, end, stepsize))
The default tick formatter should do a decent job rounding the tick values to a sensible number of significant digits. However, if you wish to have more control over the format, you can define your own formatter. For example,
ax.xaxis.set_major_formatter(ticker.FormatStrFormatter('%0.1f'))
Here's a runnable example:
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.ticker as ticker
x = [0,5,9,10,15]
y = [0,1,2,3,4]
fig, ax = plt.subplots()
ax.plot(x,y)
start, end = ax.get_xlim()
ax.xaxis.set_ticks(np.arange(start, end, 0.712123))
ax.xaxis.set_major_formatter(ticker.FormatStrFormatter('%0.1f'))
plt.show()
Another approach is to set the axis locator:
import matplotlib.ticker as plticker
loc = plticker.MultipleLocator(base=1.0) # this locator puts ticks at regular intervals
ax.xaxis.set_major_locator(loc)
There are several different types of locator depending upon your needs.
Here is a full example:
import matplotlib.pyplot as plt
import matplotlib.ticker as plticker
x = [0,5,9,10,15]
y = [0,1,2,3,4]
fig, ax = plt.subplots()
ax.plot(x,y)
loc = plticker.MultipleLocator(base=1.0) # this locator puts ticks at regular intervals
ax.xaxis.set_major_locator(loc)
plt.show()
I like this solution (from the Matplotlib Plotting Cookbook):
import matplotlib.pyplot as plt
import matplotlib.ticker as ticker
x = [0,5,9,10,15]
y = [0,1,2,3,4]
tick_spacing = 1
fig, ax = plt.subplots(1,1)
ax.plot(x,y)
ax.xaxis.set_major_locator(ticker.MultipleLocator(tick_spacing))
plt.show()
This solution give you explicit control of the tick spacing via the number given to ticker.MultipleLocater(), allows automatic limit determination, and is easy to read later.
In case anyone is interested in a general one-liner, simply get the current ticks and use it to set the new ticks by sampling every other tick.
ax.set_xticks(ax.get_xticks()[::2])
if you just want to set the spacing a simple one liner with minimal boilerplate:
plt.gca().xaxis.set_major_locator(plt.MultipleLocator(1))
also works easily for minor ticks:
plt.gca().xaxis.set_minor_locator(plt.MultipleLocator(1))
a bit of a mouthfull, but pretty compact
This is a bit hacky, but by far the cleanest/easiest to understand example that I've found to do this. It's from an answer on SO here:
Cleanest way to hide every nth tick label in matplotlib colorbar?
for label in ax.get_xticklabels()[::2]:
label.set_visible(False)
Then you can loop over the labels setting them to visible or not depending on the density you want.
edit: note that sometimes matplotlib sets labels == '', so it might look like a label is not present, when in fact it is and just isn't displaying anything. To make sure you're looping through actual visible labels, you could try:
visible_labels = [lab for lab in ax.get_xticklabels() if lab.get_visible() is True and lab.get_text() != '']
plt.setp(visible_labels[::2], visible=False)
This is an old topic, but I stumble over this every now and then and made this function. It's very convenient:
import matplotlib.pyplot as pp
import numpy as np
def resadjust(ax, xres=None, yres=None):
"""
Send in an axis and I fix the resolution as desired.
"""
if xres:
start, stop = ax.get_xlim()
ticks = np.arange(start, stop + xres, xres)
ax.set_xticks(ticks)
if yres:
start, stop = ax.get_ylim()
ticks = np.arange(start, stop + yres, yres)
ax.set_yticks(ticks)
One caveat of controlling the ticks like this is that one does no longer enjoy the interactive automagic updating of max scale after an added line. Then do
gca().set_ylim(top=new_top) # for example
and run the resadjust function again.
I developed an inelegant solution. Consider that we have the X axis and also a list of labels for each point in X.
Example:
import matplotlib.pyplot as plt
x = [0,1,2,3,4,5]
y = [10,20,15,18,7,19]
xlabels = ['jan','feb','mar','apr','may','jun']
Let's say that I want to show ticks labels only for 'feb' and 'jun'
xlabelsnew = []
for i in xlabels:
if i not in ['feb','jun']:
i = ' '
xlabelsnew.append(i)
else:
xlabelsnew.append(i)
Good, now we have a fake list of labels. First, we plotted the original version.
plt.plot(x,y)
plt.xticks(range(0,len(x)),xlabels,rotation=45)
plt.show()
Now, the modified version.
plt.plot(x,y)
plt.xticks(range(0,len(x)),xlabelsnew,rotation=45)
plt.show()
Pure Python Implementation
Below's a pure python implementation of the desired functionality that handles any numeric series (int or float) with positive, negative, or mixed values and allows for the user to specify the desired step size:
import math
def computeTicks (x, step = 5):
"""
Computes domain with given step encompassing series x
# params
x - Required - A list-like object of integers or floats
step - Optional - Tick frequency
"""
xMax, xMin = math.ceil(max(x)), math.floor(min(x))
dMax, dMin = xMax + abs((xMax % step) - step) + (step if (xMax % step != 0) else 0), xMin - abs((xMin % step))
return range(dMin, dMax, step)
Sample Output
# Negative to Positive
series = [-2, 18, 24, 29, 43]
print(list(computeTicks(series)))
[-5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45]
# Negative to 0
series = [-30, -14, -10, -9, -3, 0]
print(list(computeTicks(series)))
[-30, -25, -20, -15, -10, -5, 0]
# 0 to Positive
series = [19, 23, 24, 27]
print(list(computeTicks(series)))
[15, 20, 25, 30]
# Floats
series = [1.8, 12.0, 21.2]
print(list(computeTicks(series)))
[0, 5, 10, 15, 20, 25]
# Step – 100
series = [118.3, 293.2, 768.1]
print(list(computeTicks(series, step = 100)))
[100, 200, 300, 400, 500, 600, 700, 800]
Sample Usage
import matplotlib.pyplot as plt
x = [0,5,9,10,15]
y = [0,1,2,3,4]
plt.plot(x,y)
plt.xticks(computeTicks(x))
plt.show()
Notice the x-axis has integer values all evenly spaced by 5, whereas the y-axis has a different interval (the matplotlib default behavior, because the ticks weren't specified).
Generalisable one liner, with only Numpy imported:
ax.set_xticks(np.arange(min(x),max(x),1))
Set in the context of the question:
import numpy as np
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
x = [0,5,9,10,15]
y = [0,1,2,3,4]
ax.plot(x,y)
ax.set_xticks(np.arange(min(x),max(x),1))
plt.show()
How it works:
fig, ax = plt.subplots() gives the ax object which contains the axes.
np.arange(min(x),max(x),1) gives an array of interval 1 from the min of x to the max of x. This is the new x ticks that we want.
ax.set_xticks() changes the ticks on the ax object.
xmarks=[i for i in range(1,length+1,1)]
plt.xticks(xmarks)
This worked for me
if you want ticks between [1,5] (1 and 5 inclusive) then replace
length = 5
Since None of the above solutions worked for my usecase, here I provide a solution using None (pun!) which can be adapted to a wide variety of scenarios.
Here is a sample piece of code that produces cluttered ticks on both X and Y axes.
# Note the super cluttered ticks on both X and Y axis.
# inputs
x = np.arange(1, 101)
y = x * np.log(x)
fig = plt.figure() # create figure
ax = fig.add_subplot(111)
ax.plot(x, y)
ax.set_xticks(x) # set xtick values
ax.set_yticks(y) # set ytick values
plt.show()
Now, we clean up the clutter with a new plot that shows only a sparse set of values on both x and y axes as ticks.
# inputs
x = np.arange(1, 101)
y = x * np.log(x)
fig = plt.figure() # create figure
ax = fig.add_subplot(111)
ax.plot(x, y)
ax.set_xticks(x)
ax.set_yticks(y)
# which values need to be shown?
# here, we show every third value from `x` and `y`
show_every = 3
sparse_xticks = [None] * x.shape[0]
sparse_xticks[::show_every] = x[::show_every]
sparse_yticks = [None] * y.shape[0]
sparse_yticks[::show_every] = y[::show_every]
ax.set_xticklabels(sparse_xticks, fontsize=6) # set sparse xtick values
ax.set_yticklabels(sparse_yticks, fontsize=6) # set sparse ytick values
plt.show()
Depending on the usecase, one can adapt the above code simply by changing show_every and using that for sampling tick values for X or Y or both the axes.
If this stepsize based solution doesn't fit, then one can also populate the values of sparse_xticks or sparse_yticks at irregular intervals, if that is what is desired.
You can loop through labels and show or hide those you want:
for i, label in enumerate(ax.get_xticklabels()):
if i % interval != 0:
label.set_visible(False)

Offset secondary axis in matplotlib

I'm trying to bring together to different plot settings in matplotlib. I found nice examples for each of them in the matplotlib example gallery/documentation and stack but I couldn't find anything on my specific problem.
So what I know so far is, how to add one or more axes with offset y-axis for plotting different data with respect to the same x-axis, by using ax.twinx(). The third y-axis is called parasite axis in the example Parasite axis demo. However, if you want to add an additional axis which is just a scaled version of the existing one, you can use ax.secondary_yaxis(), as shown in the Secondary axis demo. There is no additional data to be plotted.
What I could not achieve so far is a secondary y-axis which is offset from the original one. This can be very helpful to make plots more readable across scientific communities. For instance, while some scientists use frequency as reference for the electromagnetic spectrum, others use the wavelength or the wavenumber. Afsar [1] used a very convenient axis labeling which includes all the three variables in the same plot:
I would like to the something similar, just on the y-axis instead of the x-axis. Is there a way to offset the secondary axis from the primary axis? I tried a few parameters but couldn't figure it out.
Thank you for any help!
[1] Afsar, Mohammed Nurul. “Precision Millimeter-Wave Measurements of Complex Refractive Index, Complex Dielectric Permittivity, and Loss Tangent of Common Polymers.” IEEE Transactions on Instrumentation and Measurement IM–36, no. 2 (June 1987): 530–36. https://doi.org/10.1109/TIM.1987.6312733.
[1]:
A complete example. The third-to-last line is the relevant one.
import matplotlib.pyplot as plt
import numpy as np
import datetime
dates = [datetime.datetime(2018, 1, 1) + datetime.timedelta(hours=k * 6)
for k in range(240)]
temperature = np.random.randn(len(dates)) * 4 + 6.7
fig, ax = plt.subplots(constrained_layout=True)
ax.plot(dates, temperature)
ax.set_ylabel(r'$T\ [^oC]$')
plt.xticks(rotation=70)
def date2yday(x):
"""Convert matplotlib datenum to days since 2018-01-01."""
y = x - mdates.date2num(datetime.datetime(2018, 1, 1))
return y
def yday2date(x):
"""Return a matplotlib datenum for *x* days after 2018-01-01."""
y = x + mdates.date2num(datetime.datetime(2018, 1, 1))
return y
secax_x = ax.secondary_xaxis('top', functions=(date2yday, yday2date))
secax_x.set_xlabel('yday [2018]')
def celsius_to_fahrenheit(x):
return x * 1.8 + 32
def fahrenheit_to_celsius(x):
return (x - 32) / 1.8
secax_y = ax.secondary_yaxis(
'right', functions=(celsius_to_fahrenheit, fahrenheit_to_celsius))
secax_y.set_ylabel(r'$T\ [^oF]$')
def celsius_to_anomaly(x):
return (x - np.mean(temperature))
def anomaly_to_celsius(x):
return (x + np.mean(temperature))
# document use of a float for the position:
secax_y2 = ax.secondary_yaxis(
1.2, functions=(celsius_to_anomaly, anomaly_to_celsius))
secax_y2.set_ylabel(r'$T - \overline{T}\ [^oC]$')
plt.show()
Here is another approach, although maybe it's more of a hack:
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import FuncFormatter
#FuncFormatter
def twin1_formatter(x, pos):
return f'{x/np.pi*180:.0f}'
#FuncFormatter
def twin2_formatter(x, pos):
return f'{x/np.pi:.1f} $\pi$'
data = np.arange(0, 2*np.pi, 0.1)
fig, ax = plt.subplots()
twin1 = ax.twiny()
twin1.spines['top'].set_position(('axes', 1.2))
twin1.set_xlabel('Degrees')
twin1.xaxis.set_major_formatter(FuncFormatter(twin1_formatter))
twin2 = ax.twiny()
twin2.set_xlabel('Pies')
twin2.xaxis.set_major_formatter(FuncFormatter(twin2_formatter))
twin2.xaxis.set_ticks(np.array([0, 1/2, 1, 3/2, 2])*np.pi)
ax.plot(data, np.sin(data))
ax.set_xlabel('Radians')
twin1.set_xlim(ax.get_xlim())
twin2.set_xlim(ax.get_xlim())
fig.show()

matplotlib: change axis ticks of ndim histogram plotted with seaborn.heatmap

Motivation:
I'm trying to visualize a dataset of many n-dimensional vectors (let's say i have 10k vectors with n=300 dimensions). What i'd like to do is calculate a histogram for each of the n dimensions and plot it as a single line in a bins*n heatmap.
So far i've got this:
import numpy as np
import matplotlib
from matplotlib import pyplot as plt
%matplotlib inline
import seaborn as sns
# sample data:
vectors = np.random.randn(10000, 300) + np.random.randn(300)
def ndhist(vectors, bins=500):
limits = (vectors.min(), vectors.max())
hists = []
dims = vectors.shape[1]
for dim in range(dims):
h, bins = np.histogram(vectors[:, dim], bins=bins, range=limits)
hists.append(h)
hists = np.array(hists)
fig = plt.figure(figsize=(16, 9))
sns.heatmap(hists)
axes = fig.gca()
axes.set(ylabel='dimensions', xlabel='values')
print(dims)
print(limits)
ndhist(vectors)
This generates the following output:
300
(-6.538069472429366, 6.52159540162285)
Problem / Question:
How can i change the axes ticks?
for the y-axis i'd like to simply change this back to matplotlib's default, so it picks nice ticks like 0, 50, 100, ..., 250 (bonus points for 299 or 300)
for the x-axis i'd like to convert the shown bin indices into the bin (left) boundaries, then, as above, i'd like to change this back to matplotlib's default selection of some "nice" ticks like -5, -2.5, 0, 2.5, 5 (bonus points for also including the actual limits -6.538, 6.522)
Own solution attempts:
I've tried many things like the following already:
def ndhist_axlabels(vectors, bins=500):
limits = (vectors.min(), vectors.max())
hists = []
dims = vectors.shape[1]
for dim in range(dims):
h, bins = np.histogram(vectors[:, dim], bins=bins, range=limits)
hists.append(h)
hists = np.array(hists)
fig = plt.figure(figsize=(16, 9))
sns.heatmap(hists, yticklabels=False, xticklabels=False)
axes = fig.gca()
axes.set(ylabel='dimensions', xlabel='values')
#plt.xticks(np.linspace(*limits, len(bins)), bins)
plt.xticks(range(len(bins)), bins)
axes.xaxis.set_major_locator(matplotlib.ticker.AutoLocator())
plt.yticks(range(dims+1), range(dims+1))
axes.yaxis.set_major_locator(matplotlib.ticker.AutoLocator())
print(dims)
print(limits)
ndhist_axlabels(vectors)
As you can see however, the axes labels are pretty wrong. My guess is that the extent or limits are somewhere stored in the original axis, but lost when switching back to the AutoLocator. Would greatly appreciate a nudge in the right direction.
Maybe you're overthinking this. To plot image data, one can use imshow and get the ticking and formatting for free.
import numpy as np
from matplotlib import pyplot as plt
# sample data:
vectors = np.random.randn(10000, 300) + np.random.randn(300)
def ndhist(vectors, bins=500):
limits = (vectors.min(), vectors.max())
hists = []
dims = vectors.shape[1]
for dim in range(dims):
h, _ = np.histogram(vectors[:, dim], bins=bins, range=limits)
hists.append(h)
hists = np.array(hists)
fig, ax = plt.subplots(figsize=(16, 9))
extent = [limits[0], limits[-1], hists.shape[0]-0.5, -0.5]
im = ax.imshow(hists, extent=extent, aspect="auto")
fig.colorbar(im)
ax.set(ylabel='dimensions', xlabel='values')
ndhist(vectors)
plt.show()
If you read the docs, you will notice that the xticklabels/yticklabels arguments are overloaded, such that if you provide an integer instead of a string, it will interpret the argument as xtickevery/ytickevery and place ticks only at the corresponding locations. So in your case, seaborn.heatmap(hists, yticklabels=50) fixes your y-axis problem.
Regarding your xtick labels, I would simply provide them explictly:
xtickevery = 50
xticklabels = ['{:.1f}'.format(b) if ii%xtickevery == 0 else '' for ii, b in enumerate(bins)]
sns.heatmap(hists, yticklabels=50, xticklabels=xticklabels)
Finally came up with a version that works for me for now and uses AutoLocator based on some simple linear mapping...
def ndhist(vectors, bins=1000, title=None):
t = time.time()
limits = (vectors.min(), vectors.max())
hists = []
dims = vectors.shape[1]
for dim in range(dims):
h, bs = np.histogram(vectors[:, dim], bins=bins, range=limits)
hists.append(h)
hists = np.array(hists)
fig = plt.figure(figsize=(16, 12))
sns.heatmap(
hists,
yticklabels=50,
xticklabels=False
)
axes = fig.gca()
axes.set(
ylabel=f'dimensions ({dims} total)',
xlabel=f'values (min: {limits[0]:.4g}, max: {limits[1]:.4g}, {bins} bins)',
title=title,
)
def val_to_idx(val):
# calc (linearly interpolated) index loc for given val
return bins*(val - limits[0])/(limits[1] - limits[0])
xlabels = [round(l, 3) for l in limits] + [
v for v in matplotlib.ticker.AutoLocator().tick_values(*limits)[1:-1]
]
# drop auto-gen labels that might be too close to limits
d = (xlabels[4] - xlabels[3])/3
if (xlabels[1] - xlabels[-1]) < d:
del xlabels[-1]
if (xlabels[2] - xlabels[0]) < d:
del xlabels[2]
xticks = [val_to_idx(val) for val in xlabels]
axes.set_xticks(xticks)
axes.set_xticklabels([f'{l:.4g}' for l in xlabels])
plt.show()
print(f'histogram generated in {time.time() - t:.2f}s')
ndhist(np.random.randn(100000, 300), bins=1000, title='randn')
Thanks to Paul for his answer giving me the idea.
If there's an easier or more elegant solution, i'd still be interested though.

How to set fixed spaces between ticks in maptlotlib

I am preparing a graph of latency percentile results. This is my pd.DataFrame looks like:
import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
%matplotlib inline
result = pd.DataFrame(np.random.randint(133000, size=(5,3)), columns=list('ABC'), index=[99.0, 99.9, 99.99, 99.999, 99.9999])
I am using this function (commented lines are different pyplot methods I have already tried to achieve my goal):
def plot_latency_time_bar(result):
ind = np.arange(4)
means = []
stds = []
for index, row in result.iterrows():
means.append(np.mean([row[0]//1000, row[1]//1000, row[2]//1000]))
stds.append(np .std([row[0]//1000, row[1]//1000, row[2]//1000]))
plt.bar(result.index.values, means, 0.2, yerr=stds, align='center')
plt.xlabel('Percentile')
plt.ylabel('Latency')
plt.xticks(result.index.values)
# plt.xticks(ind, ('99.0', '99.9', '99.99', '99.999', '99.99999'))
# plt.autoscale(enable=False, axis='x', tight=False)
# plt.axis('auto')
# plt.margins(0.8, 0)
# plt.semilogx(basex=5)
plt.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)
fig = plt.gcf()
fig.set_size_inches(15.5, 10.5)
And here is the figure:
As you can see bars for all percentiles above 99.0 overlaps and are completely unreadable. I would like to set some fixed space between ticks to have a same space between all of them.
Since you're using pandas, you can do all this from within that library:
means = df.mean(axis=1)/1000
stds = df.std(axis=1)/1000
means.plot.bar(yerr=stds, fc='b')
# Make some room for the x-axis tick labels
plt.subplots_adjust(bottom=0.2)
plt.show()
Not wishing to take anything away from xnx's answer (which is the most elegant way to do things given that you're working in pandas, and therefore likely the best answer for you) but the key insight you're missing is that, in matplotlib, the x positions of the data you're plotting and the x tick labels are independent things. If you say:
nominalX = np.arange( 1, 6 ) ** 2
y = np.arange( 1, 6 ) ** 4
positionalX = np.arange(len(y))
plt.bar( positionalX, y ) # graph y against the numbers 1..n
plt.gca().set(xticks=positionalX + 0.4, xticklabels=nominalX) # ...but superficially label the X values as something else
then that's different from tying positions to your nominal X values:
plt.bar( nominalX, y )
Note that I added 0.4 to the x position of the ticks, because that's half the default width of the bars bar( ..., width=0.8 )—so the ticks end up in the middle of the bar.

How to plot multiple lines in single graph python

I have a three-dimensional array.
The first dimension has 4 elements.
The second dimension has 10 elements.
The third dimension has 5 elements.
I want to plot the contents of this array as follows.
Each element of the first dimension gets its own graph (four graphs on the page)
The values of the second dimension correspond to the y values of the graphs. (there are 10 lines on each graph)
The values of the third dimension correspond to the x values of the graphs (each of the 10 lines has 5 x values)
I'm pretty new to python, and even newer to graphing.
I figured out how to correctly load my array with the data...and I'm not even trying to get the 'four graphs on one page' aspect working.
For now I just want one graph to work correctly.
Here's what I have so far (once my array is set up, and I've correctly loaded my arrays. Right now the graph shows up, but it's blank, and the x-axis includes negative values. None of my data is negative)
for n in range(1):
for m in range(10):
for o in range(5):
plt.plot(quadnumcounts[n][m][o])
plt.xlabel("Trials")
plt.ylabel("Frequency")
plt.show()
Any help would be really appreciated!
Edit. Further clarification. Let's say my array is loaded as follows:
myarray[0][1][0] = 22
myarray[0][1][1] = 10
myarray[0][1][2] = 15
myarray[0][1][3] = 25
myarray[0][1][4] = 13
I want there to be a line, with the y values 22, 10, 15, 25, 13, and the x values 1, 2, 3, 4, 5 (since it's 0 indexed, I can just +1 before printing the label)
Then, let's say I have
myarray[0][2][0] = 10
myarray[0][2][1] = 17
myarray[0][2][2] = 9
myarray[0][2][3] = 12
myarray[0][2][4] = 3
I want that to be another line, following the same rules as the first.
Here's how to make the 4 plots with 10 lines in each.
import matplotlib.pyplot as plt
for i, fig_data in enumerate(quadnumcounts):
# Set current figure to the i'th subplot in the 2x2 grid
plt.subplot(2, 2, i + 1)
# Set axis labels for current figure
plt.xlabel('Trials')
plt.ylabel('Frequency')
for line_data in fig_data:
# Plot a single line
xs = [i + 1 for i in range(len(line_data))]
ys = line_data
plt.plot(xs, ys)
# Now that we have created all plots, show the result
plt.show()
Here is the example of creating subplots of your data. You have not provided the dataset so I used x to be an angle from 0 to 360 degrees and the y to be the trigonemetric functions of x (sine and cosine).
Code example:
import numpy as np
import pylab as plt
x = np.arange(0, 361) # 0 to 360 degrees
y = []
y.append(1*np.sin(x*np.pi/180.0))
y.append(2*np.sin(x*np.pi/180.0))
y.append(1*np.cos(x*np.pi/180.0))
y.append(2*np.cos(x*np.pi/180.0))
z = [[x, y[0]], [x, y[1]], [x, y[2]], [x, y[3]]] # 3-dimensional array
# plot graphs
for count, (x_data, y_data) in enumerate(z):
plt.subplot(2, 2, count + 1)
plt.plot(x_data, y_data)
plt.xlabel('Angle')
plt.ylabel('Amplitude')
plt.grid(True)
plt.show()
Output:
UPDATE:
Using the sample date you provided in your update, you could proceed as follows:
import numpy as np
import pylab as plt
y1 = (10, 17, 9, 12, 3)
y2 = (22, 10, 15, 25, 13)
y3 = tuple(reversed(y1)) # generated for explanation
y4 = tuple(reversed(y2)) # generated for explanation
mydata = [y1, y2, y3, y4]
# plot graphs
for count, y_data in enumerate(mydata):
x_data = range(1, len(y_data) + 1)
print x_data
print y_data
plt.subplot(2, 2, count + 1)
plt.plot(x_data, y_data, '-*')
plt.xlabel('Trials')
plt.ylabel('Frequency')
plt.grid(True)
plt.show()
Note that the dimensions are slightly different from yours. Here they are such that mydata[0][0] == 10, mydata[1][3] == 25 etc. The output is show below:

Categories