I am creating two plots using matplotlib, each of them is a subplot showing two metrics on the same axis.
I'm trying to run them so they show as two charts but in one graphic, so that when I save the graphic I see both plots. At the moment, running the second plot overwrites the first in memory so I can only ever save the second.
How can I plot them together?
My code is below.
plot1 = plt.figure()
fig,ax1 = plt.subplots()
ax1.plot(dfSat['time'],dfSat['wind_at_altitude'], 'b-', label = "speed", linewidth = 5.0)
plt.title('Wind Speeds - Saturday - {}'.format(windloc))
plt.xlabel('Time of day')
plt.ylabel('Wind speed (mph)')
ax1.plot(dfSat['time'],dfSat['gust_at_altitude'], 'r-', label = "gust", linewidth = 5.0)
plt.legend(loc="upper right")
ax1.text(0.05, 0.95, calcmeassat, transform=ax1.transAxes, fontsize=30,
verticalalignment='top')
plt.ylim((0,100))
plot2 = plt.figure()
fig,ax2 = plt.subplots()
ax2.plot(dfSun['time'],dfSun['wind_at_altitude'], 'b-', label = "speed", linewidth = 5.0)
plt.title('Wind Speeds - Sunday - {}'.format(windloc))
plt.xlabel('Time of day')
plt.ylabel('Wind speed (mph)')
ax2.plot(dfSun['time'],dfSun['gust_at_altitude'], 'r-', label = "gust", linewidth = 5.0)
plt.legend(loc="upper right")
ax2.text(0.05, 0.95, calcmeassun, transform=ax2.transAxes, fontsize=30,
verticalalignment='top')
plt.ylim((0,100))
As mentioned, in your case you only need one level of subplots, e.g., nrows=1, ncols=2.
However, in matplotlib 3.4+ there is such a thing as "subplotting subplots" called subfigures, which makes it easier to implement nested layouts, e.g.:
How to create row titles for subplots
How to share colorbars within some subplots
How to share xlabels within some subplots
Subplots
For your simpler use case, create 1x2 subplots with ax1 on the left and ax2 on the right:
# create 1x2 subplots
fig, (ax1, ax2) = plt.subplots(nrows=1, ncols=2, figsize=(16, 4))
# plot saturdays on the left
dfSat.plot(ax=ax1, x='date', y='temp_min')
dfSat.plot(ax=ax1, x='date', y='temp_max')
ax1.set_ylim(-20, 50)
ax1.set_title('Saturdays')
# plot sundays on the right
dfSun.plot(ax=ax2, x='date', y='temp_min')
dfSun.plot(ax=ax2, x='date', y='temp_max')
ax2.set_ylim(-20, 50)
ax2.set_title('Sundays')
Subfigures
Say you want something more complicated like having the left side show 2012 with its own suptitle and right side to show 2015 with its own suptitle.
Create 1x2 subfigures (left subfig_l and right subfig_r) with 2x1 subplots on the left (top ax_lt and bottom ax_lb) and 2x1 subplots on the right (top ax_rt and bottom ax_rb):
# create 1x2 subfigures
fig = plt.figure(constrained_layout=True, figsize=(12, 5))
(subfig_l, subfig_r) = fig.subfigures(nrows=1, ncols=2, wspace=0.07)
# create top/box axes in left subfig
(ax_lt, ax_lb) = subfig_l.subplots(nrows=2, ncols=1)
# plot 2012 saturdays on left-top axes
dfSat12 = dfSat.loc[dfSat['date'].dt.year.eq(2012)]
dfSat12.plot(ax=ax_lt, x='date', y='temp_min')
dfSat12.plot(ax=ax_lt, x='date', y='temp_max')
ax_lt.set_ylim(-20, 50)
ax_lt.set_ylabel('Saturdays')
# plot 2012 sundays on left-top axes
dfSun12 = dfSun.loc[dfSun['date'].dt.year.eq(2012)]
dfSun12.plot(ax=ax_lb, x='date', y='temp_min')
dfSun12.plot(ax=ax_lb, x='date', y='temp_max')
ax_lb.set_ylim(-20, 50)
ax_lb.set_ylabel('Sundays')
# set suptitle for left subfig
subfig_l.suptitle('2012', size='x-large', weight='bold')
# create top/box axes in right subfig
(ax_rt, ax_rb) = subfig_r.subplots(nrows=2, ncols=1)
# plot 2015 saturdays on left-top axes
dfSat15 = dfSat.loc[dfSat['date'].dt.year.eq(2015)]
dfSat15.plot(ax=ax_rt, x='date', y='temp_min')
dfSat15.plot(ax=ax_rt, x='date', y='temp_max')
ax_rt.set_ylim(-20, 50)
ax_rt.set_ylabel('Saturdays')
# plot 2015 sundays on left-top axes
dfSun15 = dfSun.loc[dfSun['date'].dt.year.eq(2015)]
dfSun15.plot(ax=ax_rb, x='date', y='temp_min')
dfSun15.plot(ax=ax_rb, x='date', y='temp_max')
ax_rb.set_ylim(-20, 50)
ax_rb.set_ylabel('Sundays')
# set suptitle for right subfig
subfig_r.suptitle('2015', size='x-large', weight='bold')
Sample data for reference:
import pandas as pd
from vega_datasets import data
df = data.seattle_weather()
df['date'] = pd.to_datetime(df['date'])
dfSat = df.loc[df['date'].dt.weekday.eq(5)]
dfSun = df.loc[df['date'].dt.weekday.eq(6)]
It doesn't work like that. Subplots are what they are called; plots inside a main plot.
That means if you need two subplots; then you need one plot containing two subplots in it.
# figure object NOT plot object
# useful when you want only one plot NO subplots
fig = plt.figure()
# 2 subplots inside 1 plot
# 1 row, 2 columns
fig, [ax1, ax2] = plt.subplots(1, 2)
# then call plotting method on each axis object to
# create plot on that subplot
sns.histplot(...., ax=ax1)
sns.violinplot(..., ax=ax2)
# or using matplotlib like this
ax1.plot()
ax2.plot()
Learn more about subplots
Related
I'd like to represent two datasets on the same plot, one as a line as one as a binned barplot. I can do each individually:
tobar = pd.melt(pd.DataFrame(np.random.randn(1000).cumsum()))
tobar["bins"] = pd.qcut(tobar.index, 20)
bp = sns.barplot(data=tobar, x="bins", y="value")
toline = pd.melt(pd.DataFrame(np.random.randn(1000).cumsum()))
lp = sns.lineplot(data=toline, x=toline.index, y="value")
But when I try to combine them, of course the x axis gets messed up:
fig, ax = plt.subplots()
ax2 = ax.twinx()
bp = sns.barplot(data=tobar, x="bins", y="value", ax=ax)
lp = sns.lineplot(data=toline, x=toline.index, y="value", ax=ax2)
bp.set(xlabel=None)
I also can't seem to get rid of the bin labels.
How can I get these two informations on the one plot?
This answer explains why it's better to plot the bars with matplotlib.axes.Axes.bar instead of sns.barplot or pandas.DataFrame.bar.
In short, the xtick locations correspond to the actual numeric value of the label, whereas the xticks for seaborn and pandas are 0 indexed, and don't correspond to the numeric value.
This answer shows how to add bar labels.
ax2 = ax.twinx() can be used for the line plot if needed
Works the same if the line plot is different data.
Tested in python 3.11, pandas 1.5.2, matplotlib 3.6.2, seaborn 0.12.1
Imports and DataFrame
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import numpy as np
# test data
np.random.seed(2022)
df = pd.melt(pd.DataFrame(np.random.randn(1000).cumsum()))
# create the bins
df["bins"] = pd.qcut(df.index, 20)
# add a column for the mid point of the interval
df['mid'] = df.bins.apply(lambda row: row.mid.round().astype(int))
# pivot the dataframe to calculate the mean of each interval
pt = df.pivot_table(index='mid', values='value', aggfunc='mean').reset_index()
Plot 1
# create the figure
fig, ax = plt.subplots(figsize=(30, 7))
# add a horizontal line at y=0
ax.axhline(0, color='black')
# add the bar plot
ax.bar(data=pt, x='mid', height='value', width=4, alpha=0.5)
# set the labels on the xticks - if desired
ax.set_xticks(ticks=pt.mid, labels=pt.mid)
# add the intervals as labels on the bars - if desired
ax.bar_label(ax.containers[0], labels=df.bins.unique(), weight='bold')
# add the line plot
_ = sns.lineplot(data=df, x=df.index, y="value", ax=ax, color='tab:orange')
Plot 2
fig, ax = plt.subplots(figsize=(30, 7))
ax.axhline(0, color='black')
ax.bar(data=pt, x='mid', height='value', width=4, alpha=0.5)
ax.set_xticks(ticks=pt.mid, labels=df.bins.unique(), rotation=45)
ax.bar_label(ax.containers[0], weight='bold')
_ = sns.lineplot(data=df, x=df.index, y="value", ax=ax, color='tab:orange')
Plot 3
The bar width is the width of the interval
fig, ax = plt.subplots(figsize=(30, 7))
ax.axhline(0, color='black')
ax.bar(data=pt, x='mid', height='value', width=50, alpha=0.5, ec='k')
ax.set_xticks(ticks=pt.mid, labels=df.bins.unique(), rotation=45)
ax.bar_label(ax.containers[0], weight='bold')
_ = sns.lineplot(data=df, x=df.index, y="value", ax=ax, color='tab:orange')
I want to draw a barplot with 3 different y values which belong to RMSE, R2 and MAPE metrics.
My dataframe is;
DLscores = {"GRU":[293.7372606050454,0.961253983114077,86281.57826775634],
"LSTM":[285.9872902525968,0.9632715628933957,81788.73018602304],
"LSTM_Attention":[266.6285102384448,0.9680756432778241,71090.76247197246],
"TCN":[219.30770326715282,0.9784018398981137,48095.868712313546],
"Hybrid":[216.97781461699145,0.978858312741761,47079.372035965505]}
I am able to do this with linegraph. However when I change it to bar, they overlaps. My line plot code is;
# Create figure and axis #1
fig, ax1 = plt.subplots(figsize=(16,10))
# plot line chart on axis #1
p1, = ax1.plot(DLscores.columns, DLscores.iloc[1], color='blue')
ax1.set_ylabel('R2')
#ax1.set_ylim(0, 25)
#ax1.legend(['R2'], loc="upper left")
ax1.yaxis.label.set_color(p1.get_color())
ax1.yaxis.label.set_fontsize(14)
ax1.tick_params(axis='y', colors=p1.get_color(), labelsize=14)
# set up the 2nd axis
ax2 = ax1.twinx()
# plot bar chart on axis #2
p2, = ax2.plot(DLscores.columns, DLscores.iloc[0], color='green')
ax2.grid(False) # turn off grid #2
ax2.set_ylabel('RMSE')
#ax2.set_ylim(0, 90)
#ax2.legend(['RMSE'], loc="upper center")
ax2.yaxis.label.set_color(p2.get_color())
ax2.yaxis.label.set_fontsize(14)
ax2.tick_params(axis='y', colors=p2.get_color(), labelsize=14)
# set up the 3rd axis
ax3 = ax1.twinx()
# Offset the right spine of ax3. The ticks and label have already been placed on the right by twinx above.
ax3.spines.right.set_position(("axes", 1.2))
# Plot line chart on axis #3
p3, = ax3.plot(DLscores.columns, DLscores.iloc[2], color='red')
ax3.grid(False) # turn off grid #3
ax3.set_ylabel('MAPE')
#ax3.set_ylim(0, 8)
#ax3.legend(['MAPE'], loc="upper right")
ax3.yaxis.label.set_color(p3.get_color())
ax3.yaxis.label.set_fontsize(14)
ax3.tick_params(axis='y', colors=p3.get_color(), labelsize=14)
plt.show()
Output:
I also tried seaborn (I couldn't figure it out how can I merge it with "hue"), but code and result is in below:
# plot line chart on axis #1
ax1 = sns.barplot(
x=DLscores.index,
y=DLscores['RMSE'],
color='blue'
)
ax1.set_ylabel('RMSE')
#ax1.set_ylim(0, 8)
ax1.legend(['RMSE'], loc="upper left")
ax1.yaxis.label.set_color('blue')
ax1.yaxis.label.set_fontsize(14)
ax1.tick_params(axis='y', colors='blue', labelsize=14)
# set up the 2nd axis
ax2 = ax1.twinx()
# plot bar chart on axis #2
sns.barplot(
x=DLscores.index,
y=DLscores['R2'],
color='orange',
ax = ax2 # Pre-existing axes for the plot
)
ax2.grid(False) # turn off grid #2
ax2.set_ylabel('R2')
#ax2.set_ylim(0, 90)
ax2.legend(['R2'], loc="upper center")
ax2.yaxis.label.set_color('orange')
ax2.yaxis.label.set_fontsize(14)
ax2.tick_params(axis='y', colors='orange', labelsize=14)
# set up the 3rd axis
ax3 = ax1.twinx()
# Offset the right spine of ax3. The ticks and label have already been placed on the right by twinx above.
ax3.spines.right.set_position(("axes", 1.15))
# Plot line chart on axis #3
p3 = sns.barplot(
x=DLscores.index,
y=DLscores['MAPE'],
color='red',
ax = ax3 # Pre-existing axes for the plot
)
ax3.grid(False) # turn off grid #3
ax3.set_ylabel('MAPE')
#ax3.set_ylim(0, 8)
ax3.legend(['MAPE'], loc="upper right")
ax3.yaxis.label.set_color('red')
ax3.yaxis.label.set_fontsize(14)
ax3.tick_params(axis='y', colors='red', labelsize=14)
plt.show()
I assume the problem is clear.
How can I set the labels on the extra axes?
The ticks and labels should be the same on all 4 axes. I'm doing something wrong... Thanks!
import matplotlib.pyplot as plt
plt.rcParams['text.usetex'] = True
plt.figure(figsize=(5,5))
f, ax1 = plt.subplots()
ax2 = ax1.twinx()
ax3 = ax1.twiny()
plt.show()
# create reusable ticks and labels
ticks = [0,1/2,3.14159/4,3.14159/2,1]
labels = [r"$0$", r"$\displaystyle\frac{1}{2}$", r"$\displaystyle\frac{\pi}{4}$", r"$\displaystyle\frac{\pi}{2}$", r"$1$"]
# Version 1: twinx() + xaxis.set_ticks()
plt.figure(figsize=(5,5))
f, ax1 = plt.subplots()
ax2 = ax1.twinx()
ax3 = ax1.twiny()
ax1.xaxis.set_ticks(ticks, labels=labels)
ax1.yaxis.set_ticks(ticks, labels=labels)
ax2.xaxis.set_ticks(ticks, labels=labels)
ax3.yaxis.set_ticks(ticks, labels=labels)
plt.show()
# Version 2: twinx() + set_xticklabels)()
plt.figure(figsize=(5,5))
f, ax1 = plt.subplots()
ax2 = ax1.twinx()
ax3 = ax1.twiny()
ax1.set_xticks(ticks)
ax1.set_xticklabels(labels)
ax1.set_yticks(ticks)
ax1.set_yticklabels(labels)
ax2.set_xticks(ticks)
ax2.set_xticklabels(labels)
ax3.set_yticks(ticks)
ax3.set_yticklabels(labels)
plt.show()
Confused: How come ax1 has both xaxis and yaxis, while ax2, ax3 do not appear to?
A unintuitive solution based on matplotlib.axes.Axes.twinx:
Create a new Axes with an invisible x-axis and an independent y-axis
positioned opposite to the original one (i.e. at right).
This means unintuitively (at least for me) you have to switch x/y at the .twin call.
unintuitively not concerning the general matplotlib twinx functionality, but concerning such a manual ticks and label assignment
To highlight that a bit more I used ax2_x and ax3_y in the code.
Disclaimer: Not sure if that will break your plot intention when data is added.
Probably at least you have to take special care with the data assignment to those twin axes - keeping that "axis switch" in mind.
Also keep that axis switch" in mind when assigning different ticks and labels to the x/y axis.
But for now I think that's the plot you were looking for:
Code:
import matplotlib.pyplot as plt
plt.rcParams['text.usetex'] = True
# create reusable ticks and labels
ticks = [0,1/2,3.14159/4,3.14159/2,1]
labels = [r"$0$", r"$\displaystyle\frac{1}{2}$", r"$\displaystyle\frac{\pi}{4}$", r"$\displaystyle\frac{\pi}{2}$", r"$1$"]
plt.figure(figsize=(5,5))
f, ax1 = plt.subplots()
ax1.xaxis.set_ticks(ticks, labels=labels)
ax1.yaxis.set_ticks(ticks, labels=labels)
ax2_x = ax1.twiny() # switch
ax3_y = ax1.twinx() # switch
ax2_x.xaxis.set_ticks(ticks, labels=labels)
ax3_y.yaxis.set_ticks(ticks, labels=labels)
plt.show()
Or switch the x/yaxis.set_ticks - with the same effect:
On second thought, I assume that's the preferred way to do it, especially when data comes into play.
ax2_x = ax1.twinx()
ax3_y = ax1.twiny()
ax2_x.yaxis.set_ticks(ticks, labels=labels) # switch
ax3_y.xaxis.set_ticks(ticks, labels=labels) # switch
In case you don't intend to use the twin axis functionality (that means having different data with different scaling assigned to those axis) but 'only' want the ticks and labels on all 4 axis for better plot readability:
Solution based on answer of ImportanceOfBeingErnest with the same plot result:
import matplotlib.pyplot as plt
plt.rcParams['text.usetex'] = True
# create reusable ticks and labels
ticks = [0,1/2,3.14159/4,3.14159/2,1]
labels = [r"$0$", r"$\displaystyle\frac{1}{2}$", r"$\displaystyle\frac{\pi}{4}$", r"$\displaystyle\frac{\pi}{2}$", r"$1$"]
plt.figure(figsize=(5,5))
f, ax1 = plt.subplots()
ax1.xaxis.set_ticks(ticks, labels=labels)
ax1.yaxis.set_ticks(ticks, labels=labels)
ax1.tick_params(axis="x", bottom=True, top=True, labelbottom=True, labeltop=True)
ax1.tick_params(axis="y", left=True, right=True, labelleft=True, labelright=True)
plt.show()
ax2 = ax1.twinx() shares the x-axis with ax1.
ax3 = ax1.twiny() shares the y-axis with ax1.
As a result, the two lines where you set ax2.xaxis and ax3.yaxis's ticks and ticklabels are redundant with the changes you already applied on ax1.
import matplotlib.pyplot as plt
plt.rcParams['text.usetex'] = False # My computer doesn't have LaTeX, don't mind me.
# Create reusable ticks and labels.
ticks = [0, 1/2, 3.14159/4, 3.14159/2, 1]
labels = [r"$0$", r"$\frac{1}{2}$", r"$\frac{\pi}{4}$", r"$\frac{\pi}{2}$", r"$1$"]
# Set the ticks and ticklabels for each axis.
fig = plt.figure(figsize=(5,5))
ax1 = fig.add_subplot()
ax2 = ax1.twinx()
ax3 = ax1.twiny()
for axis in (ax1.xaxis,
ax1.yaxis,
ax2.yaxis,
ax3.xaxis):
axis.set_ticks(ticks)
axis.set_ticklabels(labels)
fig.show()
Notice that if I comment out the work on ax2 and ax3, we get exactly what you have in your question:
for axis in (ax1.xaxis, ax1.yaxis,
# ax2.yaxis,
# ax3.xaxis,
):
axis.set_ticks(ticks)
axis.set_ticklabels(labels)
Now let's ruin ax1 via modifications on ax2, just to show that the bound between twins works well:
ax2.xaxis.set_ticks(range(10))
ax2.xaxis.set_ticklabels(tuple("abcdefghij"))
I have an issue with setting the x labels while using twinx function. My original data is a pandas dataframe, namely, df, which has 3 attributes, "name"=product name, "sold"=number of items sold, and "revenue". the name is a pandas series (like "2 shampoo"), but I can't set it to be x tick label (see pic below). How could I set the x labels to display the product's names?
fig = plt.figure() # Create matplotlib figure
ax = fig.add_subplot(111) # Create matplotlib axes
ax2 = ax.twinx() # Create another axes that shares the same x-axis as ax.
width = 0.4
df.sold.plot(kind='bar', color='red', ax=ax, width=width, position=1, rot=90)
df.revenue.plot(kind='bar', color='blue', ax=ax2, width=width, position=0, rot=90)
# print(type(df['name']), "\n", df['name'])
ax.set_ylabel('Sold')
ax2.set_ylabel('Revenue')
ax.legend(['Sold'], loc='upper left')
ax2.legend(['Revenue'], loc='upper right')
plt.show()
You will need to set the labels for X-axis using the set_xticklabels() to show the fields. Add this line after plotting the graph.
ax.set_xticklabels(df.Name)
and you will get the below plot.
Fairly new to plotting need help
have this DATAFRAME that I'm working on. trying to change the pace on my left y_axis to be 5 instead of 10 but I guess 'AxesSubplot' object has no attribute 'yticks' so I can't use
ax.yticks(np.arange(0, max(GDP['GDP'])+5, 5))
This is my Code ( the plotting part)
fig = plt.figure() # Create matplotlib figure
ax = fig.add_subplot(111) # Create matplotlib axes
ax2 = ax.twinx() # Create another axes that shares the same x-axis as ax.
width = 0.7
newdf.GDP.plot(kind='bar', color='#8D99FB', ax=ax, width=width)
newdf.Unemployment.plot(kind='line', color='red', ax=ax2)
ax.set_ylabel('GDP over The years in billions of dollars')
#ax.yticks(np.arange(0, max(GDP['GDP'])+5, 5))
ax2.set_ylabel('Percentage of Unemployment/total Population')
ax.set_xticklabels(newdf.Year.tolist())
ax.set_xlim(-width,len(newdf.Year.tolist()))
plt.title('GDP over The years in billions of dollars')
'''
ax.yticks(np.arange(0, max(GDP['GDP'])+5, 5))
'''
plt.show()
Thanks