I have 2 sets of boxplots, one set in blue color and another in red color. I want the legend to show the label for each set of boxplots, i.e.
Legend:
-blue box- A, -red box- B
Added labels='A' and labels='B' within sns.boxplot(), but didn't work with error message "No artists with labels found to put in legend. Note that artists whose label start with an underscore are ignored when legend() is called with no argument". How do I add the labels?
enter image description here
code for the inserted image:
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
x = list(range(1,13))
n = 40
index = [item for item in x for i in range(n)]
np.random.seed(123)
df = pd.DataFrame({'A': np.random.normal(30, 2, len(index)),
'B': np.random.normal(10, 2, len(index))},
index=index)
red_diamond = dict(markerfacecolor='r', marker='D')
blue_dot = dict(markerfacecolor='b', marker='o')
plt.figure(figsize=[10,5])
ax = plt.gca()
ax1 = sns.boxplot( x=df.index, y=df['A'], width=0.5, color='red', \
boxprops=dict(alpha=.5), flierprops=red_diamond, labels='A')
ax2 = sns.boxplot( x=df.index, y=df['B'], width=0.5, color='blue', \
boxprops=dict(alpha=.5), flierprops=blue_dot, labels='B')
plt.ylabel('Something')
plt.legend(loc="center", fontsize=8, frameon=False)
plt.show()
Here are the software versions I am using: seaborn version 0.11.2. matplotlib version 3.5.1. python version 3.10.1
The following approach sets a label via the boxprops, and creates a legend using part of ax.artists. (Note that ax, ax1 and ax2 of the question's code are all pointing to the same subplot, so here only ax is used.)
import matplotlib.pyplot as plt
import seaborn as sns
import pandas as pd
import numpy as np
x = np.arange(1, 13)
index = np.repeat(x, 40)
np.random.seed(123)
df = pd.DataFrame({'A': np.random.normal(30, 2, len(index)),
'B': np.random.normal(10, 2, len(index))},
index=index)
red_diamond = dict(markerfacecolor='r', marker='D')
blue_dot = dict(markerfacecolor='b', marker='o')
plt.figure(figsize=[10, 5])
ax = sns.boxplot(data=df, x=df.index, y='A', width=0.5, color='red',
boxprops=dict(alpha=.5, label='A'), flierprops=red_diamond)
sns.boxplot(data=df, x=df.index, y='B', width=0.5, color='blue',
boxprops=dict(alpha=.5, label='B'), flierprops=blue_dot, ax=ax)
ax.set_ylabel('Something')
handles, labels = ax.get_legend_handles_labels()
handles = [h for h, lbl, prev in zip(handles, labels, [None] + labels) if lbl != prev]
ax.legend(handles=handles, loc="center", fontsize=8, frameon=False)
plt.show()
Alternative approaches could be:
pd.melt the dataframe to long form, so hue could be used; a problem here is that then the legend wouldn't take the alpha from the boxprops into account; also setting different fliers wouldn't be supported
create a legend from custom handles
I am working on a project where I would like to read sensor data from a CSV file and do a live graph.
I am using Matplotlib for the graphing and Pandas for the data handling.
For the CSV I am using:
Column 0= Pass/Fail Boolean
Column 1= Time in %h:%m:%s format.
Column 3= Error Code (int64)
When I run the script I get a "ValueError: values must be a 1D array".
I believe its coming from the time data, but when i check the dtype it is a datetime64 as expected. My program is below:
from itertools import count
import pandas as pd
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
plt.style.use('fivethirtyeight')
x_vals = []
y_vals = []
index = count()
def animate(i):
# Use Pandas to Read CSV and create a Dataframe. Use KWARGS to choose columns, and then
specify name and type of data.
data = pd.read_csv('C:/Python/20220124.csv',usecols=[0, 1, 3], names=["Pass", "Time",
"Error Code"], header= None, parse_dates=[1], dtype={"Pass": 'boolean', "Error Code":
'Int64'})
pd.to_datetime(data['Time'])
y1 = data['Pass']
x1 = data['Time']
y2 = data['Error Code']
# Pyplot Clear Axes
plt.cla()
#Pyplot Plot data in line graphs
plt.plot(x1, y1, label='Pass/Fail', lw=3, c='c', marker='o', markersize=4, mfc='k')
plt.plot(x1, y2, label='Error Code', lw=2, ls='--', c='k')
plt.legend(loc='upper left')
plt.tight_layout()
#Pyplot Get Current Axes
ax = plt.gca()
ani = FuncAnimation(plt.gcf(), animate, interval=1000)
plt.tight_layout()
plt.show()
You can do this using only pandas. Pandas also contain a pre-built function for visualization :
df = data[['Error Code', 'Time']] # Create a pandas series contain the data that will be ploted
df.set_index('Time', inplace = True) # set the time as an index (it will serve as x-axis)
df.plot() # plot the graph
I struggle hard to succeed in plotting a dot-line between the median values (and min and max) per type of stacked violin distributions.
I tried superposing a violin plot with a seaborn.lineplot but it failed. I'm not sure with this approach that I can draw dot-lines and also link min and max of distributions of the same type. I also tried to use seaborn.lineplot but here the challenge is to plot min and max of the distribution at each x-axis value.
Here is a example dataset and the code for the violin plot in seaborn
import seaborn as sns
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
x=[0.2,0.2,0.2,0.2,0.2,0.2,0.2,0.2,0.2,0.2,0.2,0.2,0.4,0.4,0.4,0.4,0.4,0.4,0.4,0.4,0.4,0.4,0.4,0.4,0.6,0.6,0.6,0.6,0.6,0.6,0.6,0.6,0.6,0.6,0.6,0.6,0.8,0.8,0.8,0.8,0.8,0.8,0.8,0.8,0.8,0.8,0.8,0.8]
cate=['a','a','a','a','b','b','b','b','c','c','c','c','a','a','a','a','b','b','b','b','c','c','c','c','a','a','a','a','b','b','b','b','c','c','c','c','a','a','a','a','b','b','b','b','c','c','c','c']
y=[1.1,1.12,1.13,1.13,3.1,3.12,3.13,3.13,5.1,5.12,5.13,5.13,2.2,2.22,2.25,2.23,4.2,4.22,4.25,4.23,6.2,6.22,6.25,6.23,2.2,2.22,2.24,2.23,4.2,4.22,4.24,4.23,6.2,6.22,6.24,6.23,1.1,1.13,1.14,1.12,3.1,3.13,3.14,3.12,5.1,5.13,5.14,5.12]
my_pal =['red','green', 'purple']
df = pd.DataFrame({'x': x, 'Type': cate, 'y': y})
ax=sns.catplot(y='y', x='x',data=df, hue='Type', palette=my_pal, kind="violin",dodge =False)
sns.lineplot(y='y', x='x',data=df, hue='Type', palette=my_pal, ci=100,legend=False)
plt.show()
but it plots line only on a reduce part of the left of the plot. Is there a trick to superpose lineplot with violin plot?
For the line plot, 'x' is considered numerical. However, for the violin plot 'x' is considered categorical (positioned at 0, 1, 2, ...).
A solution is to convert 'x' to strings to have both plots consider it as categorical.
import seaborn as sns
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
my_pal = ['red', 'green', 'purple']
N = 40
df = pd.DataFrame({'x': np.random.randint(1, 6, N*3) * 0.2,
'y': np.random.uniform(0, 1, N*3) + np.tile([2, 4, 6], N),
'Type': np.tile(list('abc'), N)})
df['x'] = [f'{x:.1f}' for x in df['x']]
ax = sns.violinplot(y='y', x='x', data=df, hue='Type', palette=my_pal, dodge=False)
ax = sns.lineplot(y='y', x='x', data=df, hue='Type', palette=my_pal, ci=100, legend=False, ax=ax)
ax.margins(0.15) # slightly more padding for x and y axis
ax.legend(bbox_to_anchor=(1.01, 1), loc='upper left')
plt.tight_layout()
plt.show()
I would like to produce a figure like this one using matplotlib:
(source: peltiertech.com)
My data are in a pandas DataFrame, and I've gotten as far as a regular stacked barchart, but I can't figure out how to do the part where each category is given its own y-axis baseline.
Ideally I would like the vertical scale to be exactly the same for all the subplots and move the panel labels off to the side so there can be no gaps between the rows.
I haven't exactly replicated what you want but this should get you pretty close.
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import numpy as np
#create dummy data
cols = ['col'+str(i) for i in range(10)]
ind = ['ind'+str(i) for i in range(10)]
df = pd.DataFrame(np.random.normal(loc=10, scale=5, size=(10, 10)), index=ind, columns=cols)
#create plot
sns.set_style("whitegrid")
axs = df.plot(kind='bar', subplots=True, sharey=True,
figsize=(6, 5), legend=False, yticks=[],
grid=False, ylim=(0, 14), edgecolor='none',
fontsize=14, color=[sns.xkcd_rgb["brownish red"]])
plt.text(-1, 100, "The y-axis label", fontsize=14, rotation=90) # add a y-label with custom positioning
sns.despine(left=True) # get rid of the axes
for ax in axs: # set the names beside the axes
ax.lines[0].set_visible(False) # remove ugly dashed line
ax.set_title('')
sername = ax.get_legend_handles_labels()[1][0]
ax.text(9.8, 5, sername, fontsize=14)
plt.suptitle("My panel chart", fontsize=18)
I am having some issues adding labels to the legend. For some reason matplotlib is ignoring the labels I create in the dataframe. Any help?
pandas version: 0.13.0
matplotlib version: 1.3.1
import pandas as pd
%matplotlib inline
import matplotlib.pyplot as plt
# Sample dataframe
d = {'date': [pd.to_datetime('1/1/2013'), pd.to_datetime('1/1/2014'), pd.to_datetime('1/1/2015')],
'number': [1,2,3],
'letter': ['A','B','C']}
df = pd.DataFrame(d)
####################
fig, axes = plt.subplots(nrows=1, ncols=2, figsize=(13, 10))
fig.subplots_adjust(hspace=2.0) ## Create space between plots
# Chart 1
df.plot(ax=axes[0], label='one')
# Chart 2
df.set_index('date')['number'].plot(ax=axes[1], label='two')
# add a little sugar
axes[0].set_title('This is the title')
axes[0].set_ylabel('the y axis')
axes[0].set_xlabel('the x axis')
axes[0].legend(loc='best')
axes[1].legend(loc='best');
The problem is that Chart 1 is returning the legend as "number" and I want it to say "one".
Will illustrate this for first axis. You may repeat for the second.
In [72]: fig, axes = plt.subplots(nrows=1, ncols=2, figsize=(13, 10))
Get a reference to the axis
In [73]: ax=df.plot(ax=axes[0])
Get the legend
In [74]: legend = ax.get_legend()
Get the text of the legend
In [75]: text = legend.get_texts()[0]
Printing the current text of the legend
In [77]: text.get_text()
Out[77]: u'number'
Setting the desired text
In [78]: text.set_text("one")
Drawing to update
In [79]: plt.draw()
The following figure shows the changed legend for first axis. You may do the same for the other axis.
NB: IPython autocomplete helped a lot to figure out this answer!