Bar text is above the plot matplotlib - python

Each bar on my plot has a value above (ax.text). But if the bar is tall, the text is above the plot. How can I resize the plot (figsize doesn't help) so that the text will be inside the picture?
import numpy as np
x = np.arange(len(l))
l = [200,240,302,371,478]
l2 = [17, 20, 26, 23, 29]
fig = plt.figure(figsize=(10,8))
ax1 = fig.add_subplot(111)
ax1.bar(x,l)
totals=[]
for i in ax1.patches:
totals.append(i.get_height())
total = sum(totals)
for i in ax1.patches:
ax1.text(i.get_x()+0.1, i.get_height()+20, str(int(i.get_height())), fontsize=14, color='black')
ax2 = ax1.twinx()
ax2.plot(l2, color = 'b')
for x1, y1 in zip(x, l2):
ax2.annotate(str(y1)+'%', xy = (x1-0.1,y1+1 ))
ax2.grid(False)
ax2.set_yticks([-25, -10, -5,0,5,10,15,20,25,30])
plt.show()
UPD: added code and picture

You have to use plt.ylim(ymin, ymax) to change minimum and maximum of you showed Y axis. I added two next lines for both plots, they add extra 10% of Y range at the top:
ymin, ymax = plt.ylim()
plt.ylim(ymin, ymax + 0.1 * (ymax - ymin))
You may also add different (not both 10%) amount of percents for both plots to avoid collision of them.
Full fixed code below:
import numpy as np, matplotlib.pyplot as plt
l = [200,240,302,371,478]
l2 = [17, 20, 26, 23, 29]
x = np.arange(len(l))
fig = plt.figure(figsize=(10,8))
ax1 = fig.add_subplot(111)
ax1.bar(x,l)
# Next two lines added
ymin, ymax = plt.ylim()
plt.ylim(ymin, ymax + 0.1 * (ymax - ymin))
totals=[]
for i in ax1.patches:
totals.append(i.get_height())
total = sum(totals)
for i in ax1.patches:
ax1.text(i.get_x()+0.1, i.get_height()+20, str(int(i.get_height())), fontsize=14, color='black')
ax2 = ax1.twinx()
ax2.plot(l2, color = 'b')
for x1, y1 in zip(x, l2):
ax2.annotate(str(y1)+'%', xy = (x1-0.1,y1+1 ))
ax2.grid(False)
ax2.set_yticks([-25, -10, -5,0,5,10,15,20,25,30])
# Next two lines added
ymin, ymax = plt.ylim()
plt.ylim(ymin, ymax + 0.1 * (ymax - ymin))
plt.show()
Result:

Related

Matplotlib, plot a vector of numbers as a rectangle filled with numbers

So let's say I have a vector of numbers.
np.random.randn(5).round(2).tolist()
[2.05, -1.57, 1.07, 1.37, 0.32]
I want a draw a rectangle that shows this elements as numbers in a rectangle.
Something like this:
Is there an easy way to do this in matplotlib?
A bit convoluted but you could take advantage of seaborn.heatmap, creating a white colormap:
import seaborn as sns
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.colors import LinearSegmentedColormap
data = np.random.randn(5).round(2).tolist()
linewidth = 2
ax = sns.heatmap([data], annot=True, cmap=LinearSegmentedColormap.from_list('', ['w', 'w'], N=1),
linewidths=linewidth, linecolor='black', square=True,
cbar=False, xticklabels=False, yticklabels=False)
plt.tight_layout()
plt.show()
In this case, the external lines won't be as thick as the internal ones. If needed, this can be fixed with:
ax.axhline(y=0, color='black', lw=linewidth*2)
ax.axhline(y=1, color='black', lw=linewidth*2)
ax.axvline(x=0, color='black', lw=linewidth*2)
ax.axvline(x=len(data), color='black', lw=linewidth*2)
Edit: avoid these lines and add clip_on=False to sns.heatmap (thanks/credit #JohanC)
Output:
We can add rectangles , and annotate them in a for loop.
from matplotlib import pyplot as plt
import numpy as np
# Our numbers
nums = np.random.randn(5).round(2).tolist()
# rectangle_size
rectangle_size = 2
# We want rectangles look squared, you can change if you want
plt.rcParams["figure.figsize"] = [rectangle_size * len(nums), rectangle_size]
plt.rcParams["figure.autolayout"] = True
fig = plt.figure()
ax = fig.add_subplot(111)
for i in range(len(nums)):
# We are adding rectangles
# You can change colors as you wish
plt.broken_barh([(rectangle_size * i, rectangle_size)], (0, rectangle_size), facecolors='white', edgecolor='black'
,linewidth = 1)
# We are calculating where to annotate numbers
cy = rectangle_size / 2.0
cx = rectangle_size * i + cy
# Annotation You can change color,font, etc ..
ax.annotate(str(nums[i]), (cx, cy), color='black', weight='bold', fontsize=20, ha='center', va='center')
# For squared look
plt.xlim([0, rectangle_size*len(nums)])
plt.ylim([0, rectangle_size])
# We dont want to show ticks
plt.axis('off')
plt.show()
One way using the Rectangle patch is:
import numpy as np
from matplotlib import pyplot as plt
from matplotlib.patches import Rectangle
x = np.random.randn(5).round(2).tolist()
fig, ax = plt.subplots(figsize=(9, 2)) # make figure
dx = 0.15 # edge size of box
buf = dx / 10 # buffer around edges
# set x and y limits
ax.set_xlim([0 - buf, len(x) * dx + buf])
ax.set_ylim([0 - buf, dx + buf])
# set axes as equal and turn off axis lines
ax.set_aspect("equal")
ax.axis("off")
# draw plot
for i in range(len(x)):
# create rectangle with linewidth=4
rect = Rectangle((dx * i, 0), dx, dx, facecolor="none", edgecolor="black", lw=4)
ax.add_patch(rect)
# get text position
x0, y0 = dx * i + dx / 2, dx / 2
# add text
ax.text(
x0, y0, f"{x[i]}", color="black", ha="center", va="center", fontsize=28, fontweight="bold"
)
fig.tight_layout()
fig.show()
which gives:

normal distribution curve doesn't fit well over histogram in subplots using matplotlib

I am using "plt.subplots(2, 2, sharex=True, sharey=True)" to draw a 2*2 subplots. Each subplot has two Y axis and contains normal distribution curve over a histogram. Noting I particularly set "sharex=True, sharey=True" here in order to make all subplots share the same X axis and Y axis.
After running my code, everything is fine except the second, three, and fourth subplots where the normal distribution curve doesn't fit the histogram very well (please see the figure here)
I did googling but failed to get this issue solved. However, if I set "sharex=True, sharey=False" in my code, then the figure looks correct, but all subplots use their own Y axix which isn't what I want. Please see the figure here
Hope this issue can be fixed by experts in StackOverflow. Many thanks in advance!
Below is my code:
import matplotlib.pyplot as plt
from scipy.stats import norm
def align_yaxis(ax1, v1, ax2, v2):
#adjust ax2 ylimit so that v2 in ax2 is aligned to v1 in ax1
_, y1 = ax1.transData.transform((0, v1))
_, y2 = ax2.transData.transform((0, v2))
inv = ax2.transData.inverted()
_, dy = inv.transform((0, 0)) - inv.transform((0, y1-y2))
miny, maxy = ax2.get_ylim()
ax2.set_ylim(miny+dy, maxy+dy)
def drawSingle(myax, mydf , title, offset):
num_bins = 200
xs = mydf["gap"]
x = np.linspace(-1,1,1000)
mu =np.mean(x)
sigma =np.std(xs)
n, bins, patche = myax.hist(xs, num_bins, alpha=0.8, facecolor='blue', density=False)
myax.set_ylabel('frequency',color="black",fontsize=12, weight = "bold")
myax.set_xlabel('X', fontsize=12, weight = "bold",horizontalalignment='center')
ax_twin = myax.twinx()
y_normcurve = norm.pdf(bins, mu, sigma)
ax_twin.plot(bins, y_normcurve, 'r--')
align_yaxis(myax,0,ax_twin,0)
peakpoint = norm.pdf(mu,loc=mu,scale=sigma)
plt.vlines(mu, 0, peakpoint, 'y', '--', label='example')
ax_twin.set_ylabel("probablility dense",color="black",fontsize=12, weight = "bold")
def drawSubplots(mydf1,mydf2,mydf3,mydf4, pos1,pos2,pos3,pos4, title, filename):
plt.rcParams['figure.figsize'] = (18,15 )
my_x_ticks = np.arange(-0.8, 0.8,0.1)
rows, cols = 2, 2
fig, ax = plt.subplots(2, 2, sharex=True, sharey=True)
drawSingle(ax[0][0], mydf1, "Subplot1", pos1)
drawSingle(ax[0][1], mydf2, "Subplot2", pos2)
drawSingle(ax[1][0], mydf3, "Subplot3", pos3)
drawSingle(ax[1][1], mydf4, "Subplot4", pos4)
plt.text(-1, -1, title, horizontalalignment='center', fontsize=18)
plt.show()
drawSubplots(df1, df2,df3,df4,3.2,3.1,2.7,2.85,"test9", "test9")
Here is an attempt to:
have the left y-axes being "frequency" (which is very uninformative in the case of the current bin widths) and shared among the 4 subplots
have the right y-axes be a "probability density"; note how the top of all gaussians is around y=0.02 (the twin axes can only be set at the end because the shared y axes can be updated via later subplots)
have the histogram and the normal curve aligned
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
from scipy.stats import norm
def drawSingle(myax, mydf, title):
num_bins = 200
xs = mydf["gap"]
x = np.linspace(-1, 1, 1000)
mu = np.mean(x)
sigma = np.std(xs)
n, bins, patches = myax.hist(xs, num_bins, alpha=0.8, facecolor='blue', density=False)
myax.set_ylabel('frequency', color="black", fontsize=12, weight="bold")
myax.set_xlabel('X', fontsize=12, weight="bold", horizontalalignment='center')
normalization_factor = len(xs) * (bins[1] - bins[0])
y_normcurve = norm.pdf(x, mu, sigma) * normalization_factor
myax.plot(x, y_normcurve, 'r--')
myax.vlines(mu, 0, y_normcurve.max(), 'y', '--', color='lime', label='example')
return normalization_factor
def drawSubplots(mydf1, mydf2, mydf3, mydf4, title):
plt.rcParams['figure.figsize'] = (18, 15)
fig, ax = plt.subplots(nrows=2, ncols=2, sharex=True, sharey=True)
dfs = [mydf1, mydf2, mydf3, mydf4]
norm_factors = [drawSingle(ax_i, df, title)
for ax_i, df, title in zip(ax.ravel(), dfs, ["Subplot1", "Subplot2", "Subplot3", "Subplot4"])]
for ax_i, norm_factor in zip(ax.ravel(), norm_factors):
ax_twin = ax_i.twinx()
ymax = ax_i.get_ylim()[1]
ax_twin.set_ylim(0, ymax / norm_factor)
plt.suptitle(title, fontsize=18)
plt.tight_layout()
plt.show()
df1, df2, df3, df4 = [pd.DataFrame({"gap": np.random.normal(0, 0.2, n)}) for n in [6000, 4000, 1800, 1200]]
drawSubplots(df1, df2, df3, df4, "Title")
Many thanks JohanC, you are amazing.
Based on your code, I just added a few lines of code within drawSubplots function in order to make 95% of the Gaussian curve area shaded between the lower bound and upper bound for each subplot. The following is my try. It seems that ax_twin.fill_between doesn't work normally here. As you could see from the figure that the shaded area is out of the Gaussian curve enter image description here. What I want is only to shade the area under the Gaussian curve between the lower bound and upper bound. If you don't mind, would you please check it out my mistake? Thank you very much!
import matplotlib.pyplot as plt
import math
from scipy.stats import norm
def align_yaxis(ax1, v1, ax2, v2):
#adjust ax2 ylimit so that v2 in ax2 is aligned to v1 in ax1
_, y1 = ax1.transData.transform((0, v1))
_, y2 = ax2.transData.transform((0, v2))
inv = ax2.transData.inverted()
_, dy = inv.transform((0, 0)) - inv.transform((0, y1-y2))
miny, maxy = ax2.get_ylim()
ax2.set_ylim(miny+dy, maxy+dy)
def drawSingle(myax, mydf , title):
num_bins = 200
xs = mydf["gap"]
x = np.linspace(-1,1,1000)
mu =np.mean(xs)
sigma =np.std(xs)
n, bins, patches = myax.hist(xs, num_bins, alpha=0.8, facecolor='blue', density=False)
myax.set_ylabel('Frequency', color="black", fontsize=12, weight="bold")
myax.set_xlabel(title, fontsize=12, weight="bold", horizontalalignment='center')
normalization_factor = len(xs) * (bins[1] - bins[0])
y_normcurve = norm.pdf(x, mu, sigma) * normalization_factor
myax.plot(x, y_normcurve, 'r--')
myax.vlines(mu, 0, y_normcurve.max(), 'y', '--', color='lime', label='example')
plt.xlim(-0.8,0.8)
my_x_ticks = np.arange(-0.8, 0.8,0.1)
plt.xticks(my_x_ticks)
return normalization_factor, mu, sigma
def drawSubplots(mydf1,mydf2,mydf3,mydf4, title):
plt.rcParams['figure.figsize'] = (18,15 )
norm_factors = []
mus = []
sigmas = []
my_x_ticks = np.arange(-0.8, 0.8,0.1)
rows, cols = 2, 2
fig, ax = plt.subplots(nrows=rows, ncols=cols, sharex=True, sharey=True)
dfs = [mydf1, mydf2, mydf3, mydf4]
#norm_factors = [drawSingle(ax_i, df, title)
#for ax_i, df, title in zip(ax.ravel(), dfs, ["Subplot1", "Subplot2", "Subplot3", "Subplot4"])]
for ax_i, df, title in zip(ax.ravel(), dfs, ["Subplot1", "Subplot2", "Subplot3", "Subplot4"]):
norm_factor, mu, sigma = drawSingle(ax_i, df, title)
norm_factors.append(norm_factor)
mus.append(mu)
sigmas.append(sigma)
for ax_i, norm_factor, mu, sigma in zip(ax.ravel(), norm_factors, mus, sigmas ):
ax_twin = ax_i.twinx()
xmax = ax_i.get_xlim()[1]
ax_twin.set_ylim(0, xmax / norm_factor)
ax_twin.set_ylabel("probablility dense",color="black",fontsize=12, weight = "bold")
CI_95_lower = mu - (1.96*sigma)
CI_95_upper = mu + (1.96*sigma)
px_shaded = np.arange(CI_95_lower,CI_95_upper,0.1)
ax_twin.fill_between(px_shaded,norm.pdf(px_shaded,loc=mu,scale=sigma) * norm_factor,alpha=0.75, color='pink')
area_shaded_95_CI = norm.cdf(x=CI_95_upper, loc=mu, scale=sigma)-norm.cdf(x=CI_95_lower, loc=mu, scale=sigma)
ax_twin.text(-0.06,0.01,str(round(area_shaded_95_CI*100,1))+"%", fontsize=20)
ax_twin.annotate(s=f'lower bound= {CI_95_lower:.3f}',xy=(CI_95_lower,norm.pdf(CI_95_lower,loc=mu,scale=sigma)),xytext=(-0.75,0.01),weight='bold',color='blue',\
arrowprops=dict(arrowstyle='-|>',connectionstyle='arc3',color='green'),\
fontsize=12
)
ax_twin.annotate(s=f'upper bound= {CI_95_upper:.3f}',xy=(CI_95_upper,norm.pdf(CI_95_upper,loc=mu,scale=sigma)),xytext=(0.28,0.01),weight='bold',color='blue',\
arrowprops=dict(arrowstyle='-|>',connectionstyle='arc3',color='green'),\
fontsize=12
)
ax_twin.text(0.05, 0.03, r"$\mu=" + f'{mu:.6f}' + ", \sigma=" + f'{sigma:.6f}' + "$" + ", confidence interval=95%" ,
horizontalalignment='center', fontsize=15)
plt.suptitle(title, fontsize=18)
plt.tight_layout()
plt.show()
df1, df2, df3, df4 = [pd.DataFrame({"gap": np.random.normal(0, 0.2, n)}) for n in [6000, 4000, 1800, 1200]]
drawSubplots(df1, df2, df3, df4, "Title")

How to limit lower error of bar plot to 0?

I calculated the rttMeans and rttStds arrays. However, the value of rttStds makes the lower error less than 0.
rttStds = [3.330311915835426, 3.3189677330174883, 3.3319538853150386, 3.325173772304221, 3.3374145232695813]
How to set lower error to 0 instead of -#?
The python bar plot code is bellow.
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
sns.set(rc={'figure.figsize':(18,16)},style='ticks',font_scale = 1.5,font='serif')
N = 5
ind = ['RSU1', 'RSU2', 'RSU3', 'RSU4', 'RSU5'] # the x locations for the groups
width = 0.4 # the width of the bars: can also be len(x) sequence
fig = plt.figure(figsize=(10,6))
ax = fig.add_subplot(111)
p1 = plt.bar(ind, rttMeans, width, yerr=rttStds, log=False, capsize = 16, color='green', hatch="/", error_kw=dict(elinewidth=3,ecolor='black'))
plt.margins(0.01, 0)
#Optional code - Make plot look nicer
plt.xticks(rotation=0)
i=0.18
for row in rttMeans:
plt.text(i, row, "{0:.1f}".format(row), color='black', ha="center")
i = i + 1
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
params = {'axes.titlesize':24,
'axes.labelsize':24,
'xtick.labelsize':28,
'ytick.labelsize':28,
'legend.fontsize': 24,
'axes.spines.right':False,
'axes.spines.top':False}
plt.rcParams.update(params)
plt.tick_params(axis="y", labelsize=28, labelrotation=20, labelcolor="black")
plt.tick_params(axis="x", labelsize=28, labelrotation=20, labelcolor="black")
plt.ylabel('RT Time (millisecond)', fontsize=24)
plt.title('# Participating RSUs', fontsize=24)
# plt.savefig('RSUs.pdf', bbox_inches='tight')
plt.show()
You can pass yerr as a pair [lower_errors, upper_errors] where you can control lower_errors :
lowers = np.minimum(rttStds,rttMeans)
p1 = plt.bar(ind, rttMeans, width, yerr=[lowers,rttStds], log=False, capsize = 16, color='green', hatch="/", error_kw=dict(elinewidth=3,ecolor='black'))
Output:

Having just one legend when using matplotlib zoomed_inset_axes

I'd like to make a fairly straight forward plot with 4 sets of data, two in the main plot, and two in the insert (on a different scale).
This is the starting code::
w1snr_limit = np.arange(0, 50, 0.5)
w2snr_limit = np.arange(0, 50, 0.5)
w3snr_limit = np.arange(0, 10, 0.5)
w4snr_limit = np.arange(0, 10, 0.5)
w1snr_percent = w1snr_limit**(1/2.)
w2snr_percent = w2snr_limit**(1/2.)
w3snr_percent = w3snr_limit**(1/3.)
w4snr_percent = w4snr_limit**(1/4.)
fig, ax = plt.subplots(figsize=(8.0, 8.0))
xmin = 0.00
xmax = 50.00
ymin = 0.00
ymax = 100.00
ax.scatter(w1snr_limit, w1snr_percent, s=ms, alpha=0.85, label='W1 SNR')
ax.scatter(w2snr_limit, w2snr_percent, s=ms, alpha=0.85, label='W2 SNR')
ax.set_xlim((xmin, xmax))
ax.set_ylim((ymin, ymax))
Then there would be this inset plot::
axins = zoomed_inset_axes(ax, 2.0, loc='lower right')
# sub region of the original image
x1, x2, y1, y2 = 0.0, 10., 0.0, 20.0
axins.set_xlim(x1, x2)
axins.set_ylim(y1, y2)
axins.scatter(w3snr_limit, w3snr_percent, s=ms, alpha=0.85, label='W3 SNR', color='green')
axins.scatter(w4snr_limit, w4snr_percent, s=ms, alpha=0.85, label='W4 SNR', color='red')
But then I first struggle to get the inset plot properly placed (i.e. the two x-axes are all munched up) and also it's unclear to me how you get all 4 datasets into the same legend
handles, labels = ax.get_legend_handles_labels()
handles = [handles[0], handles[1], handles[2], handles[3]]
labels = [labels[0], labels[1], labels[2],labels[3]]
ax.legend(handles,labels,loc=2)
leads to a
IndexError: list index out of range
error. Little help just to get these things sorted?
Not sure what "properly placed" means, but since the data is in the lower part of the figure, I'd suggest to use "upper right" as loc.
You need to supply the handles and labels of both the ax and the axins to the legend to have them all in the legend.
Complete example:
import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1.inset_locator import zoomed_inset_axes
w1snr_limit = w2snr_limit = np.arange(0, 50, 0.5)
w3snr_limit = w4snr_limit = np.arange(0, 10, 0.5)
w1snr_percent = w1snr_limit**(1/2.)
w2snr_percent = w2snr_limit**(1/2.)
w3snr_percent = w3snr_limit**(1/3.)
w4snr_percent = w4snr_limit**(1/4.)
fig, ax = plt.subplots(figsize=(8.0, 8.0))
xmin, xmax = 0., 50.
ymin, ymax = 0., 100.
ax.scatter(w1snr_limit, w1snr_percent, s=6, alpha=0.85, label='W1 SNR')
ax.scatter(w2snr_limit, w2snr_percent, s=6, alpha=0.85, label='W2 SNR')
ax.set_xlim((xmin, xmax))
ax.set_ylim((ymin, ymax))
axins = zoomed_inset_axes(ax, 2.0, loc='upper right')
# sub region of the original image
x1, x2, y1, y2 = 0.0, 10., 0.0, 20.0
axins.set_xlim(x1, x2)
axins.set_ylim(y1, y2)
axins.scatter(w3snr_limit, w3snr_percent, s=6, alpha=0.85, label='W3 SNR', color='green')
axins.scatter(w4snr_limit, w4snr_percent, s=6, alpha=0.85, label='W4 SNR', color='red')
handles, labels = ax.get_legend_handles_labels()
handles1, labels1 = axins.get_legend_handles_labels()
ax.legend(handles+handles1, labels+labels1, loc=2)
plt.show()

Function is not displayed correctly in matplotlib

I want to visualize a function that is discontinuous at a certain value of x (=2).
However I do not get what I hoped. My code is the following:
x = np.arange(-1, 4, 0.1)
y = 2 * x**2 / (x - 2)
df = pd.DataFrame({"x" : x , "y" : y})
% matplotlib inline
import matplotlib
from matplotlib import pyplot as plt
# Set up the graph
plt.xlabel('x')
plt.ylabel('y')
plt.xticks(np.arange(-1,4, 0.5))
plt.yticks(np.arange(-8, 8, 0.5))
plt.axhline()
plt.axvline()
plt.grid()
# Plot the function
plt.plot(df["x"], df["y"], color='red')
axes = plt.gca()
xmin = -1
xmax = 4
ymin = -8
ymax = 8
axes.set_xlim([xmin,xmax])
axes.set_ylim([ymin,ymax])
plt.axvline(2)
plt.show()
What I get is the following:
Why the y values for x > 2 do not appear?
The problem is that you've set your ylim in such a way that it cuts off the values for x > 2.
Consider the output of your function for inputs greater than 2:
f = lambda x: 2 * x**2 / (x - 2)
print([f(i) for i in np.arange(2.1, 4, 0.2)])
#[88.199999999999918, 35.266666666666644, 24.999999999999989, 20.828571428571422,
# 18.688888888888883, 17.472727272727269, 16.753846153846151, 16.333333333333332,
# 16.105882352941176, 16.010526315789473]
If you changed the ylim constraints, you'll see the plot below:
# Set up the graph
plt.xlabel('x')
plt.ylabel('y')
#plt.xticks(np.arange(-1,4, 0.5))
#plt.yticks(np.arange(-8, 8, 0.5))
plt.axhline()
plt.axvline()
plt.grid()
# Plot the function
plt.plot(df["x"], df["y"], color='red')
axes = plt.gca()
xmin = -1
xmax = 4
ymin = -8
ymax = 100
axes.set_xlim([xmin,xmax])
axes.set_ylim([ymin,ymax])
plt.axvline(2)
plt.show()

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