Several lines on the same diagram with Pandas plot() grouping - python

I have a CSV with 3 data sets, each coresponding to a line to plot. I use Pandas plot() grouping to group the entries for the 3 lines. This generates 3 separate diagrams, but I would like to plot all 3 lines on the same diagram.
The CSV:
shop,timestamp,sales
north,2023-01-01,235
north,2023-01-02,147
north,2023-01-03,387
north,2023-01-04,367
north,2023-01-05,197
south,2023-01-01,235
south,2023-01-02,98
south,2023-01-03,435
south,2023-01-04,246
south,2023-01-05,273
east,2023-01-01,197
east,2023-01-02,389
east,2023-01-03,87
east,2023-01-04,179
east,2023-01-05,298
The code (tested in Jupyter Lab):
import pandas as pd
csv = pd.read_csv('./tmp/sample.csv')
csv.timestamp = pd.to_datetime(csv.timestamp)
csv.plot(x='timestamp', by='shop')
This gives the following:
Any idea how to render them 3 on one single diagram?

You can create manually your subplot:
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
for name, df in csv.groupby('shop'):
df.plot(x='timestamp', y='sales', label=name, ax=ax)
ax.set_title('Sales')
plt.show()

[Seaborn alternative (to the native Pandas.Dataframe.plot answer]
This is posted as an alternate 'answer'; for clarity and not to lump them together.
Seaborn plots the sales per shop (designated by the hue) against the timestamp (formatted as days).
## import seaborn
import seaborn as sns
## data formater
import matplotlib.dates as mdates
## plot timestamp on horizontal (formated to days), sales on vertical
## with hue set to shop, seaborn plots sales per shop
ax = sns.lineplot(data=df_csv, x='timestamp', y='sales', hue='shop')
## set datetime to days. Ensure this is set AFTER setting ax
ax.xaxis.set_major_locator(locator=mdates.DayLocator())

Plot using the ax keyword.
df_csv.groupby('shop').plot(x='timestamp', ax=plt.gca())
Working code below.
## load libraries
import pandas as pd
import matplotlib.pyplot as plt
## load dataset
df_csv = pd.read_csv('datasets/SO_shop_timestamp_sale.csv')
## check dataset
df_csv.head(3)
df_csv.describe()
df_csv.shape
## ensure data type
df_csv.timestamp = pd.to_datetime(df_csv.timestamp)
df_csv.sales = pd.to_numeric(df_csv.sales)
## Pandas plot of sales against timestamp grouped by shop, using `ax` keyword to subplot.
df_csv.groupby('shop').plot(x='timestamp', ax=plt.gca())
## Pandas plot of timestamp and sales grouped by shop, use `ax` keyword to plot on combined axes.
df_csv.groupby('shop').plot(x='timestamp', kind='kde', ax=plt.gca())

Related

How to create multiple subplots from a wide dataframe with a function

I have a dataframe df with 4 unique UID - 1001,1002,1003,1004.
I want to write a user-defined function in python that does the following:
growth curve -plots Turbidity against Time for each unique UID. Turbidity values are the ones in the Time_1, Time_2, Time_3,Time_4 & Time_5 columns. For example, UID = 1003 will have 4 plots on each graph
Add a legend to each graph such as M+L, F+L, M+R, and F+R (from columns Gen and Type)
Add a title to each graph. For example- UID:1003 + Site:FRX
Export the graphs as a pdf or jpeg or tiff file - 4 graphs per page
# The dataset
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
import numpy as np
df= {
'Gen':['M','M','M','M','F','F','F','F','M','M','M','M','F','F','F','F'],
'Site':['FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX','FRX'],
'Type':['L','L','L','L','L','L','L','L','R','R','R','R','R','R','R','R'],
'UID':[1001,1002,1003,1004,1001,1002,1003,1004,1001,1002,1003,1004,1001,1002,1003,1004],
'Time1':[100.78,112.34,108.52,139.19,149.02,177.77,79.18,89.10,106.78,102.34,128.52,119.19,129.02,147.77,169.18,170.11],
'Time2':[150.78,162.34,188.53,197.69,208.07,217.76,229.48,139.51,146.87,182.54,189.57,199.97,229.28,244.73,269.91,249.19],
'Time3':[250.78,262.34,288.53,297.69,308.07,317.7,329.81,339.15,346.87,382.54,369.59,399.97,329.28,347.73,369.91,349.12],
'Time4':[240.18,232.14,258.53,276.69,338.07,307.74,359.16,339.25,365.87,392.48,399.97,410.75,429.08,448.39,465.15,469.33],
'Time5':[270.84,282.14,298.53,306.69,318.73,327.47,369.63,389.59,398.75,432.18,449.78,473.55,494.85,509.39,515.52,539.23]
}
df = pd.DataFrame(df,columns = ['Gen','Site','Type','UID','Time1','Time2','Time3','Time4','Time5'])
df
My attempt
# See below for my thoughts/attempt- I am open to other python libraries and approaches
def graph2pdf(inputdata):
#1. convert from wide to long
inputdata = pd.melt(df,id_vars = ['Gen','Type','UID'],var_name = 'Time',value_name = 'Turbidity')
#
cmaps = ['Reds', 'Blues', 'Greens', 'Greys','Yellows']
label_patches = []
for i, cmap in enumerate(cmaps):
# I want a growth curve not a distribution curve
sns.kdeplot(x = Time, y = Turbidity,data = data, cmap=cmaps[i]+'_d')
label_patch = mpatches.Patch(color=sns.color_palette(cmaps[i])[2],label=label)
label_patches.append(label_patch)
#2. add legend
plt.legend(handles=label_patches, loc='upper left')
#3. add title- 'UID number+ SiteName: FRX' to each of the graphs
plt.title('UID:1003+FRX')
plt.show()
#4. export as pdf file i.e 4 graphs per page
with PdfPages('turbidityvstime_pdf.pdf') as pdf:
plt.figure(figsize=(2,2)) # 4 graphs per page, I am anticipating more pages in the future
pdf.savefig() # saves the current figure into a pdf page
plt.close()
# testing the user-defined function
graph2pdf(df)
I want the graph to look something like the figure below (turbidity instead of density on the y-axis and time on the x-axis). if possible, a white or clear background is preferred
Thanks
I line plot is usually not appropriate for discrete data, because the slope of the lines can imply trends that do not exist.
This is discrete because measurements are taken at discrete moments in time, not a continuous time series.
Discrete data is best visualized with a bar plot.
Use seaborn figure-level methods like sns.catplot or sns.replot to create the figure with four subplots.
Tested in python 3.8.11, pandas 1.3.2, matplotlib 3.4.3, seaborn 0.11.2
import pandas as pd
import seaborn as sns
def graph2pdf(df):
# melt the dataframe; any column not a var or value, should be in id_vars
data = df.melt(id_vars=df.columns[:4], var_name='Time', value_name='Turbidity')
# combine Gen and Type to create label, which can be used for hue
data['label'] = data.Gen + '-' + data.Type
# plot a catplot for bars
p1 = sns.catplot(data=data, kind='bar', x='Time', y='Turbidity', hue='label', col='UID', col_wrap=2, height=3.25)
p1.fig.subplots_adjust(top=0.9) # adjust the figure
p1.fig.suptitle('UID:1003+FRX')
p1.savefig("barplots.png")
# plot a relplot for lines
p2 = sns.relplot(data=data, kind='line', x='Time', y='Turbidity', hue='label', col='UID', col_wrap=2, height=3.25, marker='o')
p2.fig.subplots_adjust(top=0.9)
p2.fig.suptitle('UID:1003+FRX')
p2.savefig("lineplots.png")
graph2pdf(df)

Reproduce simple pandas plot

I have a situation with my data. I like the behaviour of .plot() over a data frame. But sometimes it doesn't work, because the frequency of the time index is not an integer.
But reproducing the plot in matplotlib is OK. Just ugly.
The part that bother me the most is the settings of the x axis. The tick frequency and the limits. Is there any easy way that I can reproduce this behaviour in matplotlib?
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
# Create Data
f = lambda x: np.sin(0.1*x) + 0.1*np.random.randn(1,x.shape[0])
x = np.arange(0,217,0.001)
y = f(x)
# Create DataFrame
data = pd.DataFrame(y.transpose(), columns=['dp'], index=None)
data['t'] = pd.date_range('2021-01-01 14:32:09', periods=len(data['dp']),freq='ms')
data.set_index('t', inplace=True)
# Pandas plot()
data.plot()
# Matplotlib plot (ugly x-axis)
plt.plot(data.index,data['dp'])
EDIT: Basically, what I want to achieve is a similar spacing in the xtics labels, and the tight margin adjust of the values. Legends and axis title, I can do them
Pandas output
Matplotlib output
Thanks
You can use some matplotlib date utilities:
Figure.autofmt_xdate() to unrotate and center the date labels
Axis.set_major_locator() to change the interval to 1 min
Axis.set_major_formatter() to reformat as %H:%M
fig, ax = plt.subplots()
ax.plot(data.index, data['dp'])
import matplotlib.dates as mdates
fig.autofmt_xdate(rotation=0, ha='center')
ax.xaxis.set_major_locator(mdates.MinuteLocator(interval=1))
ax.xaxis.set_major_formatter(mdates.DateFormatter('%H:%M'))
# uncomment to remove the first `xtick`
# ax.set_xticks(ax.get_xticks()[1:])

Removing outliers from dataset identified in Matplotlib/Seaborn boxplot

I have produced a Boxplot/Swarmplot graph using Matplotlib/Seaborn in Pandas. Some outliers can been seen in the graph (as dots outside the "whiskers"/"fence" area). I am looking for a way to trim the dataset directly after they have been identified in the graph and without removing them from the original dataset. I do not want to simply hide the outlier dots.
Some methods have been recommended and pandas quantile looks promising but I am not sure how to implement these with the code I have been using.
My graph with the outliers.
The code I used to produce this graph. The data has been organized into the tidy format.
# Import libraries and modules
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
# Set seaborn style
sns.set(style="whitegrid", palette="colorblind")
# load length tidy data
length_tidy = pd.read_csv('results/tidy/length_tidy.csv')
score_tidy = pd.read_csv('results/tidy/score_tidy.csv')
# Define and save boxplot and swarmplot for length data
fig, ax = plt.subplots(figsize=(10,6))
ax = sns.boxplot(x='Metric', y='Length', data=length_tidy, ax=ax)
ax = sns.swarmplot(x="Metric", y="Length", data=length_tidy, color=".25")
ax.set_xlabel('Condition')
ax.set_ylabel('Length in micrometers')
plt.savefig('statistics/boxplot/length_boxplot.png', dpi=300)
fig, ax = plt.subplots(figsize=(10,6))
ax = sns.boxplot(x='Metric', y='Score', data=score_tidy, ax=ax)
ax = sns.swarmplot(x="Metric", y="Score", data=score_tidy, color=".25")
ax.set_xlabel('Condition')
ax.set_ylabel('Score')
plt.savefig('statistics/boxplot/score_boxplot.png', dpi=300)
An example of some of the data I am working with in the CSV format.
Object,Metric,Length
M11,B2A10,1.807782
MT1,B2A10,3.2207116666666664
MT1,B2A1,3.57675
MT1,B2A2,2.9474600000000004
MT1,B2A3,2.247772857142857
MT1,B2A4,3.754455
MT1,B2A5,2.716282
MT1,B2A6,2.91325
MT1,B2A7,1.24806
MT1,B2A8,2.00371875
MT1,B2A9,1.5435599999999998
MT1,B2B1,2.2051515384615388
MT1,B2B2,1.5278873333333332
MT1,B2B3,1.7283750000000002
MT1,B2B4,1.4547385714285714
MT1,B2B5,3.237578333333333
MT1,B2B6,2.47016
MT1,B2B7,2.1185947777777776
MT1,B2B8,1.8502877777777773
MT10,B2A10,3.07143
MT10,B2A1,3.34361
MT10,B2A2,2.889958333333333
MT10,B2A3,2.22087
MT10,B2A4,2.87669
MT10,B2A5,1.6745005555555557
MT10,B2A7,2.09018
MT10,B2A8,2.4947450000000004
MT10,B2B1,1.849095882352941
MT10,B2B2,1.5291758000000002
MT10,B2B5,1.6423770999999998
MT10,B2B6,1.9680385714285715
MT10,B2B7,1.7207240000000001
MT10,B2B8,2.9618275
MT12,B2A10,1.7243058333333334
MT12,B2A1,3.3938900000000003
MT12,B2A2,2.00601
MT12,B2A3,2.1720200000000003
MT12,B2A4,2.452923333333333
MT12,B2A5,2.986948
MT12,B2A7,2.08466
MT12,B2A8,1.29047
MT12,B2B1,2.528839230769232
MT12,B2B2,1.4011425454545454
MT12,B2B5,1.626078333333333
MT12,B2B6,1.074394454545455
MT12,B2B7,2.0897078571428573
MT12,B2B8,1.4102533333333336

How to plot a Python Dataframe with category values like this picture?

How can I achieve that using matplotlib?
Here is my code with the data you provided. As there's no class [they are all different, despite your first example in your question does have classes], I gave colors based on the numbers. You can definitely start alone from here, whatever result you want to achieve. You just need pandas, seaborn and matplotlib:
import pandas as pd
import seaborn as sns
import matplotlib.pyplot as plt
# import xls
df=pd.read_excel('data.xlsx')
# exclude Ranking values
df1 = df.ix[:,1:-1]
# for each element it takes the value of the xls cell
df2=df1.applymap(lambda x: float(x.split('\n')[1]))
# now plot it
df_heatmap = df2
fig, ax = plt.subplots(figsize=(15,15))
sns.heatmap(df_heatmap, square=True, ax=ax, annot=True, fmt="1.3f")
plt.yticks(rotation=0,fontsize=16);
plt.xticks(fontsize=12);
plt.tight_layout()
plt.savefig('dfcolorgraph.png')
Which produces the following picture.

Python Pandas Matplotlib Plot Colored by type value defined in single column

I have data of the following format:
import pandas as ps
table={'time':[1,2,3,4,5,1,2,3,4,5,1,2,3,4,5],\
'data':[1,1,2,2,2,1,2,3,4,5,1,2,2,2,3],\
'type':['a','a','a','a','a','b','b','b','b','b','c','c','c','c','c']}
df=ps.DataFrame(table,columns=['time','data','type']
I would like to plot data as a function of time connected as a line, but I would like each line to be a separate color for unique types. In this example, the result would be three lines: a data(time) line for each type a, b, and, c. Any guidance is appreciated.
I have been unable to produce a line with this data--pandas.scatter will produce a plot, while pandas.plot will not. I have been messing with loops to produce a plot for each type, but I have not found a straight forward way to do this. My data typically has an unknown number of unique 'type's. Does pandas and/or matpltlib have a way to create this type of plot?
Pandas plotting capabilities will allow you to do this if everything is indexed properly. However, sometimes it's easier to just use matplotlib directly:
import pandas as pd
import matplotlib.pyplot as plt
table={'time':[1,2,3,4,5,1,2,3,4,5,1,2,3,4,5],
'data':[1,1,2,2,2,1,2,3,4,5,1,2,2,2,3],
'type':['a','a','a','a','a','b','b','b','b','b','c','c','c','c','c']}
df=pd.DataFrame(table, columns=['time','data','type'])
groups = df.groupby('type')
fig, ax = plt.subplots()
for name, group in groups:
ax.plot(group['time'], group['data'], label=name)
ax.legend(loc='best')
plt.show()
If you'd prefer to use the pandas plotting wrapper, you'll need to override the legend labels:
import pandas as pd
import matplotlib.pyplot as plt
table={'time':[1,2,3,4,5,1,2,3,4,5,1,2,3,4,5],
'data':[1,1,2,2,2,1,2,3,4,5,1,2,2,2,3],
'type':['a','a','a','a','a','b','b','b','b','b','c','c','c','c','c']}
df=pd.DataFrame(table, columns=['time','data','type'])
df.index = df['time']
groups = df[['data', 'type']].groupby('type')
fig, ax = plt.subplots()
groups.plot(ax=ax, legend=False)
names = [item[0] for item in groups]
ax.legend(ax.lines, names, loc='best')
plt.show()
Just to throw in the seaborn solution.
import seaborn as sns
import matplotlib.pyplot as plt
g = sns.FacetGrid(df, hue="type", size=5)
g.map(plt.plot, "time", "data")
g.add_legend()

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