I have a sample dataset as follows;
pd.DataFrame({'Day_Duration':['Evening','Evening','Evening','Evening','Evening','Morning','Morning','Morning',
'Morning','Morning','Night','Night','Night','Night','Night','Noon','Noon','Noon',
'Noon','Noon'],'place_category':['Other','Italian','Japanese','Chinese','Burger',
'Other','Juice Bar','Donut','Bakery','American','Other','Italian','Japanese','Burger',\
'American','Other','Italian','Burger','American','Salad'],'Percent_delivery':[14.03,10.61,9.25,8.19,6.89,19.58,10.18,9.14,8.36,6.53,13.60,8.42,\
8.22,7.66,6.67,17.71,10.62,8.44,8.33,7.50]})
The goal is to draw faceted barplot with Day_duration serving as facets, hence 4 facets in total. I used the following code to achieve the same,
import seaborn as sns
#g = sns.FacetGrid(top5_places, col="Day_Duration")
g=sns.catplot(x="place_category", y="Percent_delivery", hue='place_category',col='Day_Duration',\
data=top5_places,ci=None,kind='bar',height=4, aspect=.7)
g.set_xticklabels(rotation=90)
Attached is the figure I got;
Can I kindly get help with 2 things, first is it possible to get only 5 values on the x-axis for each facet(rather than seeing all the values for each facet), second, is there a way to make the bars a bit wider. Help is appreciated.
Because you're using hue the api applies a unique color to each value of place_category, but it also expects each category to be in the plot, as shown in your image.
The final figure is a FacetGrid. Using subplot is the manual way of creating one.
In order to plot only the top n categories for each Day_Duration, each plot will need to be done individually, with a custom color map.
cmap is a dictionary with place categories as keys and colors as values. It's used so there will be one legend and each category will be colored the same for each plot.
Because we're not using the legend automatically generated by the plot, one needs to be created manually.
patches uses Patch to create each item in the legend. (e.g. the rectangle, associated with color and name).
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
from matplotlib.patches import Patch
# create a color map for unique values or place
place_cat = df.place_category.unique()
colors = sns.color_palette('husl', n_colors=10)
cmap = dict(zip(place_cat, colors))
# plot a subplot for each Day_Duration
plt.figure(figsize=(16, 6))
for i, tod in enumerate(df.Day_Duration.unique(), 1):
data = df[df.Day_Duration == tod].sort_values(['Percent_delivery'], ascending=False)
plt.subplot(1, 4, i)
p = sns.barplot(x='place_category', y='Percent_delivery', data=data, hue='place_category', palette=cmap)
p.legend_.remove()
plt.xticks(rotation=90)
plt.title(f'Day Duration: {tod}')
plt.tight_layout()
patches = [Patch(color=v, label=k) for k, v in cmap.items()]
plt.legend(handles=patches, bbox_to_anchor=(1.04, 0.5), loc='center left', borderaxespad=0)
plt.show()
Related
I need some help making a set of stacked bar charts in python with matlibplot.
Formally, my dataframe looks like this
plt.figure(figsize=(10, 14))
fig= plt.figure()
ax = sns.countplot(x="airlines",hue='typecode', data=trafic,
order=trafic.airlines.value_counts(ascending=False).iloc[:5].index,
hue_order=trafic.typecode.value_counts(ascending=False).iloc[:5].index,
)
ax.set(xlabel="Airlines code", ylabel='Count')
As written in order and hue_order, I want to isolate the 5 most present airlines and aircraft types in my database
I was advised to make a stacked bar plot to make a more presentable graph, only I don't see any functionality with Seaborn to make one, and I can't manage with matplotlib to plot it while respecting this idea of isolating the 5 airlines/aircraft types most present in my database
Thanks for your help!
The following code uses seaborn's countplot with dodge=False. This places all bars belonging to the same airline one on top of the other. In a next step, all bars are moved up to stack them:
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
import seaborn as sns
sns.set()
np.random.seed(123)
trafic = pd.DataFrame({'airlines': np.random.choice([*'abcdefghij'], 500),
'typecode': np.random.choice([*'qrstuvwxyz'], 500)})
fig = plt.figure(figsize=(10, 5))
ax = sns.countplot(x="airlines", hue='typecode', palette='rocket', dodge=False, data=trafic,
order=trafic.airlines.value_counts(ascending=False).iloc[:5].index,
hue_order=trafic.typecode.value_counts(ascending=False).iloc[:5].index)
ax.set(xlabel="Airlines code", ylabel='Count')
bottoms = {}
for bars in ax.containers:
for bar in bars:
x, y = bar.get_xy()
h = bar.get_height()
if x in bottoms:
bar.set_y(bottoms[x])
bottoms[x] += h
else:
bottoms[x] = h
ax.relim() # the plot limits need to be updated with the moved bars
ax.autoscale()
plt.show()
Note that the airlines are sorted on their total airplanes, not on their total for the 5 overall most frequent airplane types.
PS: In the question's code, plt.figure() is called twice. That first creates an empty figure with the given figsize, and then a new figure with a default figsize.
I'm trying to plot 60+ boxplots side by side from a dataframe and I was wondering if someone could suggest some possible solutions.
At the moment I have df_new, a dataframe with 66 columns, which I'm using to plot boxplots. The easiest way I found to plot the boxplots was to use the boxplot package inside pandas:
boxplot = df_new.boxplot(column=x, figsize = (100,50))
This gives me a very very tiny chart with illegible axis which I cannot seem to change the font size for, so I'm trying to do this natively in matplotlib but I cannot think of an efficient way of doing it. I'm trying to avoid creating 66 separate boxplots using something like:
fig, ax = plt.subplots(nrows = 1,
ncols = 66,
figsize = (10,5),
sharex = True)
ax[0,0].boxplot(#insert parameters here)
I actually do not not how to get the data from df_new.describe() into the boxplot function, so any tips on this would be greatly appreciated! The documentation is confusing. Not sure what x vectors should be.
Ideally I'd like to just give the boxplot function the dataframe and for it to automatically create all the boxplots by working out all the quartiles, column separations etc on the fly - is this even possible?
Thanks!
I tried to replace the boxplot with a ridge plot, which takes up less space because:
it requires half of the width
you can partially overlap the ridges
it develops vertically, so you can scroll down all the plot
I took the code from the seaborn documentation and adapted it a little bit in order to have 60 different ridges, normally distributed; here the code:
import numpy as np
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import itertools
sns.set(style="white", rc={"axes.facecolor": (0, 0, 0, 0)})
# # Create the data
n = 20
x = list(np.random.randn(1, 60)[0])
g = [item[0] + item[1] for item in list(itertools.product(list('ABCDEFGHIJ'), list('123456')))]
df = pd.DataFrame({'x': n*x,
'g': n*g})
# Initialize the FacetGrid object
pal = sns.cubehelix_palette(10, rot=-.25, light=.7)
g = sns.FacetGrid(df, row="g", hue="g", aspect=15, height=.5, palette=pal)
# Draw the densities in a few steps
g.map(sns.kdeplot, "x", clip_on=False, shade=True, alpha=1, lw=1.5, bw=.2)
g.map(sns.kdeplot, "x", clip_on=False, color="w", lw=2, bw=.2)
g.map(plt.axhline, y=0, lw=2, clip_on=False)
# Define and use a simple function to label the plot in axes coordinates
def label(x, color, label):
ax = plt.gca()
ax.text(0, .2, label, fontweight="bold", color=color,
ha="left", va="center", transform=ax.transAxes)
g.map(label, "x")
# Set the subplots to overlap
g.fig.subplots_adjust(hspace=-.25)
# Remove axes details that don't play well with overlap
g.set_titles("")
g.set(yticks=[])
g.despine(bottom=True, left=True)
plt.show()
This is the result I get:
I don't know if it will be good for your needs, in any case keep in mind that keeping so many distributions next to each other will always require a lot of space (and a very big screen).
Maybe you could try dividing the distrubutions into smaller groups and plotting them a little at a time?
I have made a simple scatterplot using matplotlib showing data from 2 numerical variables (varA and varB) with colors that I defined with a 3rd categorical string variable (col) containing 10 unique colors (corresponding to another string variable with 10 unique names), all in the same Pandas DataFrame with 100+ rows.
Is there an easy way to create a legend for this scatterplot that shows the unique colored dots and their corresponding category names? Or should I somehow group the data and plot each category in a subplot to do this? This is what I have so far:
import matplotlib.pyplot as plt
from matplotlib import colors as mcolors
varA = df['A']
varB = df['B']
col = df['Color']
plt.scatter(varA,varB, c=col, alpha=0.8)
plt.legend()
plt.show()
I had to chime in, because I could not accept that I needed a for-loop to accomplish this. It just seems really annoying and unpythonic - especially when I'm not using Pandas. However, after some searching, I found the answer. You just need to import the 'collections' package so that you can access the PathCollections class and specifically, the legend_elements() method. See implementation below:
# imports
import matplotlib.collections
import numpy as np
# create random data and numerical labels
x = np.random.rand(10,2)
y = np.random.randint(4, size=10)
# create list of categories
labels = ['type1', 'type2', 'type3', 'type4']
# plot
fig, ax = plt.subplots()
scatter = ax.scatter(x[:,0], x[:,1], c=y)
handles, _ = scatter.legend_elements(prop="colors", alpha=0.6) # use my own labels
legend1 = ax.legend(handles, labels, loc="upper right")
ax.add_artist(legend1)
plt.show()
scatterplot legend with custom labels
Source:
https://matplotlib.org/stable/gallery/lines_bars_and_markers/scatter_with_legend.html
https://matplotlib.org/stable/api/collections_api.html#matplotlib.collections.PathCollection.legend_elements
Considering, Color is the column that has all the colors and labels, you can simply do following.
colors = list(df['Color'].unique())
for i in range(0 , len(colors)):
data = df.loc[df['Color'] == colors[i]]
plt.scatter('A', 'B', data=data, color='Color', label=colors[i])
plt.legend()
plt.show()
A simple way is to group your data by color, then plot all of the data on one plot. Pandas has a built in groupby function. For example:
import matplotlib.pyplot as plt
from matplotlib import colors as mcolors
for color, group in df.groupby(['Color']):
plt.scatter(group['A'], group['B'], c=color, alpha=0.8, label=color)
plt.legend()
plt.show()
Notice that we call plt.scatter once for each grouping of data. Then we only need to call plt.legend and plt.show once all of the data is in our plot.
I am trying to plot a polar plot using Seaborn's facetGrid, similar to what is detailed on seaborn's gallery
I am using the following code:
sns.set(context='notebook', style='darkgrid', palette='deep', font='sans-serif', font_scale=1.25)
# Set up a grid of axes with a polar projection
g = sns.FacetGrid(df_total, col="Construct", hue="Run", col_wrap=5, subplot_kws=dict(projection='polar'), size=5, sharex=False, sharey=False, despine=False)
# Draw a scatterplot onto each axes in the grid
g.map(plt.plot, 'Rad', ''y axis label', marker=".", ms=3, ls='None').set_titles("{col_name}")
plt.savefig('./image.pdf')
Which with my data gives the following:
I want to keep this organisation of 5 plots per line.
The problem is that the title of each subplot overlap with the values of the ticks, same for the y axis label.
Is there a way to prevent this behaviour? Can I somehow shift the titles slightly above their current position and can I shift the y axis labels slightly on the left of their current position?
Many thanks in advance!
EDIT:
This is not a duplicate of this SO as the problem was that the title of one subplot overlapped with the axis label of another subplot.
Here my problem is that the title of one subplot overlaps with the ticks label of the same subplot and similarly the axis label overlaps with the ticks label of the same subplot.
I also would like to add that I do not care that they overlap on my jupyter notebook (as it as been created with it), however I want the final saved image with no overlap, so perhaps there is something I need to do to save the image in a slightly different format to avoid that, but I don't know what (I am only using plt.savefig to save it).
EDIT 2: If someone would like to reproduce the problem here is a minimal example:
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import seaborn as sns
sns.set()
sns.set(context='notebook', style='darkgrid', palette='deep', font='sans-serif', font_scale=1.5)
# Generate an example radial datast
r = np.linspace(0, 10000, num=100)
df = pd.DataFrame({'label': r, 'slow': r, 'medium-slow': 1 * r, 'medium': 2 * r, 'medium-fast': 3 * r, 'fast': 4 * r})
# Convert the dataframe to long-form or "tidy" format
df = pd.melt(df, id_vars=['label'], var_name='speed', value_name='theta')
# Set up a grid of axes with a polar projection
g = sns.FacetGrid(df, col="speed", hue="speed",
subplot_kws=dict(projection='polar'), size=4.5, col_wrap=5,
sharex=False, sharey=False, despine=False)
# Draw a scatterplot onto each axes in the grid
g.map(plt.scatter, "theta", "label")
plt.savefig('./image.png')
plt.show()
Which gives the following image in which the titles are not as bad as in my original problem (but still some overlap) and the label on the left hand side overlap completely.
In order to move the title a bit higher you can set at new position,
ax.title.set_position([.5, 1.1])
In order to move the ylabel a little further left, you can add some padding
ax.yaxis.labelpad = 25
To do this for the axes of the facetgrid, you'd do:
for ax in g.axes:
ax.title.set_position([.5, 1.1])
ax.yaxis.labelpad = 25
The answer provided by ImportanceOfBeingErnest in this SO question may help.
Is there a way to add a secondary legend to a scatterplot, where the size of the scatter is proportional to some data?
I have written the following code that generates a scatterplot. The color of the scatter represents the year (and is taken from a user-defined df) while the size of the scatter represents variable 3 (also taken from a df but is raw data):
import pandas as pd
colors = pd.DataFrame({'1985':'red','1990':'b','1995':'k','2000':'g','2005':'m','2010':'y'}, index=[0,1,2,3,4,5])
fig = plt.figure()
ax = fig.add_subplot(111)
for i in df.keys():
df[i].plot(kind='scatter',x='variable1',y='variable2',ax=ax,label=i,s=df[i]['variable3']/100, c=colors[i])
ax.legend(loc='upper right')
ax.set_xlabel("Variable 1")
ax.set_ylabel("Variable 2")
This code (with my data) produces the following graph:
So while the colors/years are well and clearly defined, the size of the scatter is not.
How can I add a secondary or additional legend that defines what the size of the scatter means?
You will need to create the second legend yourself, i.e. you need to create some artists to populate the legend with. In the case of a scatter we can use a normal plot and set the marker accordingly.
This is shown in the below example. To actually add a second legend we need to add the first legend to the axes, such that the new legend does not overwrite the first one.
import matplotlib.pyplot as plt
import matplotlib.colors
import numpy as np; np.random.seed(1)
import pandas as pd
plt.rcParams["figure.subplot.right"] = 0.8
v = np.random.rand(30,4)
v[:,2] = np.random.choice(np.arange(1980,2015,5), size=30)
v[:,3] = np.random.randint(5,13,size=30)
df= pd.DataFrame(v, columns=["x","y","year","quality"])
df.year = df.year.values.astype(int)
fig, ax = plt.subplots()
for i, (name, dff) in enumerate(df.groupby("year")):
c = matplotlib.colors.to_hex(plt.cm.jet(i/7.))
dff.plot(kind='scatter',x='x',y='y', label=name, c=c,
s=dff.quality**2, ax=ax)
leg = plt.legend(loc=(1.03,0), title="Year")
ax.add_artist(leg)
h = [plt.plot([],[], color="gray", marker="o", ms=i, ls="")[0] for i in range(5,13)]
plt.legend(handles=h, labels=range(5,13),loc=(1.03,0.5), title="Quality")
plt.show()
Have a look at http://matplotlib.org/users/legend_guide.html.
It shows how to have multiple legends (about halfway down) and there is another example that shows how to set the marker size.
If that doesn't work, then you can also create a custom legend (last example).