Plot Bar Graph with different Parametes in X Axis - python

I have a DataFrame like below. It has Actual and Predicted columns. I want to compare Actual Vs Predicted in Bar plot in one on one. I have confidence value for Predicted column and default for Actual confidence is 1. So, I want to keep Each row in single bar group Actual and Predicted value will be X axis and corresponding Confidence score as y value.
I am unable to get the expected plot because X axis values are not aligned or grouped to same value in each row.
Actual Predicted Confidence
0 A A 0.90
1 B C 0.30
2 C C 0.60
3 D D 0.75
Expected Bar plot.
Any hint would be appreciable. Please let me know if further details required.
What I have tried so far.
df_actual = pd.DataFrame()
df_actual['Key']= df['Actual'].copy()
df_actual['Confidence'] = 1
df_actual['Identifier'] = 'Actual'
df_predicted=pd.DataFrame()
df_predicted = df[['Predicted', 'Confidence']]
df_predicted = df_predicted.rename(columns={'Predicted': 'Key'})
df_predicted['Identifier'] = 'Predicted'
df_combined = pd.concat([df_actual,df_predicted], ignore_index=True)
df_combined
fig = px.bar(df_combined, x="Key", y="Confidence", color='Identifier',
barmode='group', height=400)
fig.show()

I have found that adjusting the data first makes it easier to get the plot I want. I have used Seaborn, hope that is ok. Please see if this code works for you. I have considered that the df mentioned above is already available. I created df2 so that it aligns to what you had shown in the expected figure. Also, I used index as the X-axis column so that the order is maintained... Some adjustments to ensure xtick names align and the legend is outside as you wanted it.
Code
vals= []
conf = []
for x, y, z in zip(df.Actual, df.Predicted, df.Confidence):
vals += [x, y]
conf += [1, z]
df2 = pd.DataFrame({'Values': vals, 'Confidence':conf}).reset_index()
ax=sns.barplot(data = df2, x='index', y='Confidence', hue='Values',dodge=False)
ax.set_xticklabels(['Actual', 'Predicted']*4)
plt.legend(bbox_to_anchor=(1.0,1))
plt.show()
Plot
Update - grouping Actual and Predicted bars
Hi #Mohammed - As we have already used up hue, I don't think there is a way to do this easily with Seaborn. You would need to use matplotlib and adjust the bar position, xtick positions, etc. Below is the code that will do this. You can change SET1 to another color map to change colors. I have also added a black outline as the same colored bars were blending into one another. Further, I had to rotate the xlables, as they were on top of one another. You can change it as per your requirements. Hope this helps...
vals = df[['Actual','Predicted']].melt(value_name='texts')['texts']
conf = [1]*4 + list(df.Confidence)
ident = ['Actual', 'Predicted']*4
df2 = pd.DataFrame({'Values': vals, 'Confidence':conf, 'Identifier':ident}).reset_index()
uvals, uind = np.unique(df2["Values"], return_inverse=1)
cmap = plt.cm.get_cmap("Set1")
fig, ax=plt.subplots()
l = len(df2)
pos = np.arange(0,l) % (l//2) + (np.arange(0,l)//(l//2)-1)*0.4
ax.bar(pos, df2["Confidence"], width=0.4, align="edge", ec="k",color=cmap(uind) )
handles=[plt.Rectangle((0,0),1,1, color=cmap(i), ec="k") for i in range(len(uvals))]
ax.legend(handles=handles, labels=list(uvals), prop ={'size':10}, loc=9, ncol=8)
pos=pos+0.2
pos.sort()
ax.set_xticks(pos)
ax.set_xticklabels(df2["Identifier"][:l], rotation=45,ha='right', rotation_mode="anchor")
ax.set_ylim(0, 1.2)
plt.show()
Output plot

I updated #Redox answer to get the exact output.
df_ = pd.DataFrame({'Labels': df.reset_index()[['Actual', 'Predicted', 'index']].values.ravel(),
'Confidence': np.array(list(zip(np.repeat(1, len(df)), df['Confidence'].values, np.repeat(0, len(df))))).ravel()})
df_.loc[df_['Labels'].astype(str).str.isdigit(), 'Labels'] = ''
plt.figure(figsize=(15, 6))
ax=sns.barplot(data = df_, x=df_.index, y='Confidence', hue='Labels',dodge=False, ci=None)
ax.set_xticklabels(['Actual', 'Predicted', '']*len(df))
plt.setp(ax.get_xticklabels(), rotation=90)
ax.tick_params(labelsize=14)
plt.legend(bbox_to_anchor=(1.05, 1), loc=2, borderaxespad=0.)
Output:
Removed loop to improve performance
Added blank bar values to look alike group chart.

Related

Pandas Python Visualization - ValueError: shape mismatch: ERROR

*Edit:
Why the right plot (Bar) is showing 50% , half black screen on the plot, wierd numbers, "garbage"... how to fix the right plot ?
here is my code:
top_series = all_data.head(50).groupby('Top Rated ')['Top Rated '].count()
top_values = top_series.values.tolist()
top_index = ['Top Rated', 'Not Top Rated']
top_colors = ['#27AE60', '#E74C3C']
rating_series = all_data.head(50).groupby('Rating')['Rating'].count()
rating_values = rating_series.values.tolist()
rating_index = ['High' , 'Low']
rating_colors = ['#F1C40F', '#27AE60']
fig, axs = plt.subplots(1,2, figsize=(16,5))
axs[0].pie(top_values, labels=top_index, autopct='%1.1f%%', shadow=True, startangle=90,
explode=(0.05, 0.05), radius=1.5, colors=top_colors, textprops={'fontsize':15})
axs[1].bar(rating_series.index, rating_series.values, color='b')
axs[1].set_xlabel('Rating')
axs[1].set_ylabel('Amount')
fig.suptitle('Does "Rating" really affect on Top Sellers ? ')
CSV cols:
Output (look at the right plot):
I suppose, that keys is a list of all keys. So it can have a different shape than the top_values.
If you would do:
axs[1].bar(top_series.index, top_series.values, color='b')
It should work well.
But, if you just want to plot the histogram, there is even shorter version, without temporary objects:
all_data['Top Rated '].value_counts().plot(kind = 'bar', ax=axs[1])
Edit: The Rating column is a numeric one, not a string one. You have to create a column which will have values High and Low. For example:
all_data['Rating_Cat'] = all_data['Rating'].apply(lambda x : 'High' if (x > 10000000 ) else 'Low')
And then use this column to plot this kind of bar plot

Different hue for each category seaborn

So, I have made a stripplot with seaborn the easiest way, with 5 different categories:
sns.set_style('whitegrid')
plt.figure(figsize=(35,20))
sns.set(font_scale = 3)
sns.stripplot(df.speed, df.routeID, hue=df.speed>50, jitter=0.2, alpha=0.5, size=10, edgecolor='black')
plt.xlabel("Speed", size=40)
plt.ylabel("route ID", size=40)
plt.title("Velocity stripplot", size=50)
Now, the thing is I want to have a different hue for each category, say speed greater than 50 kmh for first category, 30 kmh for second and so on. Is this possible? I tried to do it passing a list for hue:
hue=([("ROUTE 30">50),("ROUTE 104">0)])
but it marks: SyntaxError: invalid syntax
The thing is, I want to do it all at once (since the most obvious answer would be to plot separately) in the same plot, how can this be done?
EDIT: I followed the suggested answer. Used the same code:
plt.figure(figsize=(20,7))
my_palette = ['b' if x > 82 else 'g' for x in df.speed.values]
sns.stripplot(df.speed, df.routeID, jitter=0.2, alpha=0.5, size=8, edgecolor='black', palette = my_palette)
but didnt turned out like expected:
I dont understand what is wrong here. Any ideas?
I suggest to create separate column in df for dot color.
try this:
# INITIAL DATA
n = 1000
df = pd.DataFrame()
df['speed'] = np.random.randint(10,90,n)
df['routeID'] = np.random.choice(['ROUTE_5','ROUTE_66','ROUTE_95','ROUTE_101'], n)
# set hue indices to match your conditions
df['hue'] = 'normal' # new column with default value
df.loc[df.speed > 50, 'hue'] = 'fast'
df.loc[(df.routeID=="ROUTE_5") & (df.speed>40)|
(df.routeID=="ROUTE_66") & (df.speed>30)|
(df.routeID=="ROUTE_95") & (df.speed>60),
'hue'] = 'special'
palette = {'normal':'g','fast':'r','special':'magenta'}
sns.stripplot(x=df.speed, y=df.routeID, size=15,
hue=df.hue, palette=palette)

Box plot with divisor in Seaborn Python

I m trying to replicate this boxplot with seaborn. I wish to have a division like in the image. I thought that I can create a different Boxplot and union in a single image but isn't a great idea for computation, create many images, use a merge and delete all.
I used Seaborn to put the value on the box in this way
this is my function:
def boxplot(df, name,prot,min,max):
fig = plt.figure(figsize=(100, 20))
plt.title(name+ " RMSE from "+ str(min) +"h PSW to " + str(max) +"h PWS")
plt.ylabel("RMSE")
plt.xlabel("")
box_plot = sns.boxplot(x="Interval" ,y="RMSE", data=df, palette="Set1", showfliers = False)
ax = box_plot.axes
lines = ax.get_lines()
categories = ax.get_xticks()
for cat in categories:
# every 4th line at the interval of 6 is median line
# 0 -> p25 1 -> p75 2 -> lower whisker 3 -> upper whisker 4 -> p50 5 -> upper extreme value
y = round(lines[4+cat*5].get_ydata()[0],3)
ax.text(
cat,
y,
f'{y}',
ha='center',
va='center',
fontweight='bold',
size=70,
color='white',
bbox=dict(facecolor='#445A64'))
box_plot.figure.tight_layout()
plt.savefig("output/"+str(prot)+ str(name)+".jpg")
plt.close(fig)
I added this code too for each colour (foolish) to set the same colour for each same elements in the box. Ad example for values "15" on the x-axe I set red, and so on...
for i in range(0,len(box_plot.artists),12):
mybox = ax.artists[i]
mybox.set_facecolor('red')
for i in range(1,len(box_plot.artists),12):
mybox = ax.artists[i]
mybox.set_facecolor('orange')
I tried to use a "hue" for the category in my dataset (adding a row 15,30 near various values) but when use hue the boxplot take so many distances between them like this and I really don't like.
I tried to use "order" as same but didn't work.
This kind of plot is called "facetting" when you have a plot that's repeated for different levels of a categorical variable. In seaborn, you can create a FacetGrid, or use catplot to do this kind of things. With a bit of tweaking, you get a result that's very similar to your desired output
# dummy data
N=100
psws = [3,6,12,24,36]
times = [15,30,45,60]
df = pd.DataFrame(columns=pd.MultiIndex.from_product([psws,times], names=['PSW','Time']))
for psw in psws:
for time in times:
df[(psw,time)] = np.random.normal(loc=time, size=(N,))
# data need to be in "long-form"
df = df.melt()
g = sns.catplot(kind='box', data=df, x='Time', y='value', col='PSW', height=4, aspect=0.5, palette='Greys')
g.fig.subplots_adjust(wspace=0)
# remove the spines of the axes (except the leftmost one)
# and replace with dasehd line
for ax in g.axes.flatten()[1:]:
ax.spines['left'].set_visible(False)
[tick.set_visible(False) for tick in ax.yaxis.get_major_ticks()]
xmin,xmax = ax.get_xlim()
ax.axvline(xmin, ls='--', color='k')

Trying to set y axis labels and ticks aligned to 2D faces

This is my plot:
If I were to draw your attention to the axis labelled 'B' you'll see that everything is not as it should be.
The plots was produced using this:
def newPoly3D(self):
from matplotlib.cm import autumn
# This passes a pandas dataframe of shape (data on rows x 4 columns)
df = self.loadData()
fig = plt.figure(figsize=(10,10))
ax = fig.gca(projection='3d')
vels = [1.42,1.11,0.81,0.50]
which_joints = df.columns
L = len(which_joints)
dmin,dmax = df.min().min(),df.max().max()
dix = df.index.values
offset=-5
for i,j in enumerate(which_joints):
ax.add_collection3d(plt.fill_between(dix,df[j],
dmin,
lw=1.5,
alpha=0.3/float(i+1.),
facecolor=autumn(i/float(L))),
zs=vels[i],
zdir='y')
ax.grid(False)
ax.set_xlabel('A')
ax.set_xlim([0,df.index[-1]])
ax.set_xticks([])
ax.xaxis.set_ticklabels([])
ax.set_axis_off
ax.set_ylabel('B')
ax.set_ylim([0.4, max(vels)+0.075])
ax.set_yticks(vels)
ax.tick_params(direction='out', pad=10)
ax.set_zlabel('C')
ax.set_zlim([dmin,dmax])
ax.xaxis.labelpad = -10
ax.yaxis.labelpad = 15
ax.zaxis.labelpad = 15
# Note the inversion of the axis
plt.gca().invert_yaxis()
First I want to align the ticks on the yaxis (labelled B) with each coloured face. As you can see they are now offset slightly down.
Second I want to align the yaxis tick labels with the above, as you cans see they are currently very much offset downwards. I do not know why.
EDIT:
Here is some example data; each column represents one coloured face on the above plot.
-13.216256 -7.851065 -9.965357 -25.502654
-13.216253 -7.851063 -9.965355 -25.502653
-13.216247 -7.851060 -9.965350 -25.502651
-13.216236 -7.851052 -9.965342 -25.502647
-13.216214 -7.851038 -9.965324 -25.502639
-13.216169 -7.851008 -9.965289 -25.502623
-13.216079 -7.850949 -9.965219 -25.502592
-13.215900 -7.850830 -9.965078 -25.502529
Here we are again, with a simpler plot, reproduced with this data:
k = 10
df = pd.DataFrame(np.array([range(k),
[x + 1 for x in range(k)],
[x + 4 for x in range(k)],
[x + 9 for x in range(k)]]).T,columns=list('abcd'))
If you want to try this with the above function, comment out the df line in the function and change its argument as so def newPoly3D(df): so that you can pass the the test df above.

How to label the bars of a stacked bar plot from a pandas DataFrame? [duplicate]

I am trying to replicate the following image in matplotlib and it seems barh is my only option. Though it appears that you can't stack barh graphs so I don't know what to do
If you know of a better python library to draw this kind of thing, please let me know.
This is all I could come up with as a start:
import matplotlib.pyplot as plt; plt.rcdefaults()
import numpy as np
import matplotlib.pyplot as plt
people = ('A','B','C','D','E','F','G','H')
y_pos = np.arange(len(people))
bottomdata = 3 + 10 * np.random.rand(len(people))
topdata = 3 + 10 * np.random.rand(len(people))
fig = plt.figure(figsize=(10,8))
ax = fig.add_subplot(111)
ax.barh(y_pos, bottomdata,color='r',align='center')
ax.barh(y_pos, topdata,color='g',align='center')
ax.set_yticks(y_pos)
ax.set_yticklabels(people)
ax.set_xlabel('Distance')
plt.show()
I would then have to add labels individually using ax.text which would be tedious. Ideally I would like to just specify the width of the part to be inserted then it updates the center of that section with a string of my choosing. The labels on the outside (e.g. 3800) I can add myself later, it is mainly the labeling over the bar section itself and creating this stacked method in a nice way I'm having problems with. Can you even specify a 'distance' i.e. span of color in any way?
Edit 2: for more heterogeneous data. (I've left the above method since I find it more usual to work with the same number of records per series)
Answering the two parts of the question:
a) barh returns a container of handles to all the patches that it drew. You can use the coordinates of the patches to aid the text positions.
b) Following these two answers to the question that I noted before (see Horizontal stacked bar chart in Matplotlib), you can stack bar graphs horizontally by setting the 'left' input.
and additionally c) handling data that is less uniform in shape.
Below is one way you could handle data that is less uniform in shape is simply to process each segment independently.
import numpy as np
import matplotlib.pyplot as plt
# some labels for each row
people = ('A','B','C','D','E','F','G','H')
r = len(people)
# how many data points overall (average of 3 per person)
n = r * 3
# which person does each segment belong to?
rows = np.random.randint(0, r, (n,))
# how wide is the segment?
widths = np.random.randint(3,12, n,)
# what label to put on the segment (xrange in py2.7, range for py3)
labels = range(n)
colors ='rgbwmc'
patch_handles = []
fig = plt.figure(figsize=(10,8))
ax = fig.add_subplot(111)
left = np.zeros(r,)
row_counts = np.zeros(r,)
for (r, w, l) in zip(rows, widths, labels):
print r, w, l
patch_handles.append(ax.barh(r, w, align='center', left=left[r],
color=colors[int(row_counts[r]) % len(colors)]))
left[r] += w
row_counts[r] += 1
# we know there is only one patch but could enumerate if expanded
patch = patch_handles[-1][0]
bl = patch.get_xy()
x = 0.5*patch.get_width() + bl[0]
y = 0.5*patch.get_height() + bl[1]
ax.text(x, y, "%d%%" % (l), ha='center',va='center')
y_pos = np.arange(8)
ax.set_yticks(y_pos)
ax.set_yticklabels(people)
ax.set_xlabel('Distance')
plt.show()
Which produces a graph like this , with a different number of segments present in each series.
Note that this is not particularly efficient since each segment used an individual call to ax.barh. There may be more efficient methods (e.g. by padding a matrix with zero-width segments or nan values) but this likely to be problem-specific and is a distinct question.
Edit: updated to answer both parts of the question.
import numpy as np
import matplotlib.pyplot as plt
people = ('A','B','C','D','E','F','G','H')
segments = 4
# generate some multi-dimensional data & arbitrary labels
data = 3 + 10* np.random.rand(segments, len(people))
percentages = (np.random.randint(5,20, (len(people), segments)))
y_pos = np.arange(len(people))
fig = plt.figure(figsize=(10,8))
ax = fig.add_subplot(111)
colors ='rgbwmc'
patch_handles = []
left = np.zeros(len(people)) # left alignment of data starts at zero
for i, d in enumerate(data):
patch_handles.append(ax.barh(y_pos, d,
color=colors[i%len(colors)], align='center',
left=left))
# accumulate the left-hand offsets
left += d
# go through all of the bar segments and annotate
for j in range(len(patch_handles)):
for i, patch in enumerate(patch_handles[j].get_children()):
bl = patch.get_xy()
x = 0.5*patch.get_width() + bl[0]
y = 0.5*patch.get_height() + bl[1]
ax.text(x,y, "%d%%" % (percentages[i,j]), ha='center')
ax.set_yticks(y_pos)
ax.set_yticklabels(people)
ax.set_xlabel('Distance')
plt.show()
You can achieve a result along these lines (note: the percentages I used have nothing to do with the bar widths, as the relationship in the example seems unclear):
See Horizontal stacked bar chart in Matplotlib for some ideas on stacking horizontal bar plots.
Imports and Test DataFrame
Tested in python 3.10, pandas 1.4.2, matplotlib 3.5.1, seaborn 0.11.2
For vertical stacked bars see Stacked Bar Chart with Centered Labels
import pandas as pd
import numpy as np
# create sample data as shown in the OP
np.random.seed(365)
people = ('A','B','C','D','E','F','G','H')
bottomdata = 3 + 10 * np.random.rand(len(people))
topdata = 3 + 10 * np.random.rand(len(people))
# create the dataframe
df = pd.DataFrame({'Female': bottomdata, 'Male': topdata}, index=people)
# display(df)
Female Male
A 12.41 7.42
B 9.42 4.10
C 9.85 7.38
D 8.89 10.53
E 8.44 5.92
F 6.68 11.86
G 10.67 12.97
H 6.05 7.87
Updated with matplotlib v3.4.2
Use matplotlib.pyplot.bar_label
See How to add value labels on a bar chart for additional details and examples with .bar_label.
labels = [f'{v.get_width():.2f}%' if v.get_width() > 0 else '' for v in c ] for python < 3.8, without the assignment expression (:=).
Plotted using pandas.DataFrame.plot with kind='barh'
ax = df.plot(kind='barh', stacked=True, figsize=(8, 6))
for c in ax.containers:
# customize the label to account for cases when there might not be a bar section
labels = [f'{w:.2f}%' if (w := v.get_width()) > 0 else '' for v in c ]
# set the bar label
ax.bar_label(c, labels=labels, label_type='center')
# uncomment and use the next line if there are no nan or 0 length sections; just use fmt to add a % (the previous two lines of code are not needed, in this case)
# ax.bar_label(c, fmt='%.2f%%', label_type='center')
# move the legend
ax.legend(bbox_to_anchor=(1.025, 1), loc='upper left', borderaxespad=0.)
# add labels
ax.set_ylabel("People", fontsize=18)
ax.set_xlabel("Percent", fontsize=18)
plt.show()
Using seaborn
sns.barplot does not have an option for stacked bar plots, however, sns.histplot and sns.displot can be used to create horizontal stacked bars.
seaborn typically requires the dataframe to be in a long, instead of wide, format, so use pandas.DataFrame.melt to reshape the dataframe.
Reshape dataframe
# convert the dataframe to a long form
df = df.reset_index()
df = df.rename(columns={'index': 'People'})
dfm = df.melt(id_vars='People', var_name='Gender', value_name='Percent')
# display(dfm)
People Gender Percent
0 A Female 12.414557
1 B Female 9.416027
2 C Female 9.846105
3 D Female 8.885621
4 E Female 8.438872
5 F Female 6.680709
6 G Female 10.666258
7 H Female 6.050124
8 A Male 7.420860
9 B Male 4.104433
10 C Male 7.383738
11 D Male 10.526158
12 E Male 5.916262
13 F Male 11.857227
14 G Male 12.966913
15 H Male 7.865684
sns.histplot: axes-level plot
fig, axe = plt.subplots(figsize=(8, 6))
sns.histplot(data=dfm, y='People', hue='Gender', discrete=True, weights='Percent', multiple='stack', ax=axe)
# iterate through each set of containers
for c in axe.containers:
# add bar annotations
axe.bar_label(c, fmt='%.2f%%', label_type='center')
axe.set_xlabel('Percent')
plt.show()
sns.displot: figure-level plot
g = sns.displot(data=dfm, y='People', hue='Gender', discrete=True, weights='Percent', multiple='stack', height=6)
# iterate through each facet / supbplot
for axe in g.axes.flat:
# iteate through each set of containers
for c in axe.containers:
# add the bar annotations
axe.bar_label(c, fmt='%.2f%%', label_type='center')
axe.set_xlabel('Percent')
plt.show()
Original Answer - before matplotlib v3.4.2
The easiest way to plot a horizontal or vertical stacked bar, is to load the data into a pandas.DataFrame
This will plot, and annotate correctly, even when all categories ('People'), don't have all segments (e.g. some value is 0 or NaN)
Once the data is in the dataframe:
It's easier to manipulate and analyze
It can be plotted with the matplotlib engine, using:
pandas.DataFrame.plot.barh
label_text = f'{width}' for annotations
pandas.DataFrame.plot.bar
label_text = f'{height}' for annotations
SO: Vertical Stacked Bar Chart with Centered Labels
These methods return a matplotlib.axes.Axes or a numpy.ndarray of them.
Using the .patches method unpacks a list of matplotlib.patches.Rectangle objects, one for each of the sections of the stacked bar.
Each .Rectangle has methods for extracting the various values that define the rectangle.
Each .Rectangle is in order from left the right, and bottom to top, so all the .Rectangle objects, for each level, appear in order, when iterating through .patches.
The labels are made using an f-string, label_text = f'{width:.2f}%', so any additional text can be added as needed.
Plot and Annotate
Plotting the bar, is 1 line, the remainder is annotating the rectangles
# plot the dataframe with 1 line
ax = df.plot.barh(stacked=True, figsize=(8, 6))
# .patches is everything inside of the chart
for rect in ax.patches:
# Find where everything is located
height = rect.get_height()
width = rect.get_width()
x = rect.get_x()
y = rect.get_y()
# The height of the bar is the data value and can be used as the label
label_text = f'{width:.2f}%' # f'{width:.2f}' to format decimal values
# ax.text(x, y, text)
label_x = x + width / 2
label_y = y + height / 2
# only plot labels greater than given width
if width > 0:
ax.text(label_x, label_y, label_text, ha='center', va='center', fontsize=8)
# move the legend
ax.legend(bbox_to_anchor=(1.05, 1), loc='upper left', borderaxespad=0.)
# add labels
ax.set_ylabel("People", fontsize=18)
ax.set_xlabel("Percent", fontsize=18)
plt.show()
Example with Missing Segment
# set one of the dataframe values to 0
df.iloc[4, 1] = 0
Note the annotations are all in the correct location from df.
For this case, the above answers work perfectly. The issue I had, and didn't find a plug-and-play solution online, was that I often have to plot stacked bars in multi-subplot figures, with many values, which tend to have very non-homogenous amplitudes.
(Note: I work usually with pandas dataframes, and matplotlib. I couldn't make the bar_label() method of matplotlib to work all the times.)
So, I just give a kind of ad-hoc, but easily generalizable solution. In this example, I was working with single-row dataframes (for power-exchange monitoring purposes per hour), so, my dataframe (df) had just one row.
(I provide an example figure to show how this can be useful in very densely-packed plots)
[enter image description here][1]
[1]: https://i.stack.imgur.com/9akd8.png
'''
This implementation produces a stacked, horizontal bar plot.
df --> pandas dataframe. Columns are used as the iterator, and only the firs value of each column is used.
waterfall--> bool: if True, apart from the stack-direction, also a perpendicular offset is added.
cyclic_offset_x --> list (of any length) or None: loop through these values to use as x-offset pixels.
cyclic_offset_y --> list (of any length) or None: loop through these values to use as y-offset pixels.
ax --> matplotlib Axes, or None: if None, creates a new axis and figure.
'''
def magic_stacked_bar(df, waterfall=False, cyclic_offset_x=None, cyclic_offset_y=None, ax=None):
if isinstance(cyclic_offset_x, type(None)):
cyclic_offset_x = [0, 0]
if isinstance(cyclic_offset_y, type(None)):
cyclic_offset_y = [0, 0]
ax0 = ax
if isinstance(ax, type(None)):
fig, ax = plt.subplots()
fig.set_size_inches(19, 10)
cycler = 0;
prev = 0 # summation variable to make it stacked
for c in df.columns:
if waterfall:
y = c ; label = "" # bidirectional stack
else:
y = 0; label = c # unidirectional stack
ax.barh(y=y, width=df[c].values[0], height=1, left=prev, label = label)
prev += df[c].values[0] # add to sum-stack
offset_x = cyclic_offset_x[divmod(cycler, len(cyclic_offset_x))[1]]
offset_y = cyclic_offset_y[divmod(cycler, len(cyclic_offset_y))[1]]
ax.annotate(text="{}".format(int(df[c].values[0])), xy=(prev - df[c].values / 2, y),
xytext=(offset_x, offset_y), textcoords='offset pixels',
ha='center', va='top', fontsize=8,
arrowprops=dict(facecolor='black', shrink=0.01, width=0.3, headwidth=0.3),
bbox=dict(boxstyle='round', facecolor='grey', alpha=0.5))
cycler += 1
if not waterfall:
ax.legend() # if waterfall, the index annotates the columns. If
# waterfall ==False, the legend annotates the columns
if isinstance(ax0, type(None)):
ax.set_title("Voi la")
ax.set_xlabel("UltraWatts")
plt.show()
else:
return ax
''' (Sometimes, it is more tedious and requires some custom functions to make the labels look alright.
'''
A, B = 80,80
n_units = df.shape[1]
cyclic_offset_x = -A*np.cos(2*np.pi / (2*n_units) *np.arange(n_units))
cyclic_offset_y = B*np.sin(2*np.pi / (2*n_units) * np.arange(n_units)) + B/2

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