Is there a simple way of creating histograms for a continuous variable (mpg) that is filtered by a categorical variable (cyl=4,8)? So essentially I need two histograms for mpg grouped by cyl, one for cyl=4 and one for cyl=8.
Here is an example from a different dataset:
import numpy as np
import pandas as pd
import seaborn as sns
data = pd.DataFrame()
data[4] = np.random.normal(0,10,300)
data[8] = np.random.normal(20,11,300)
sns.distplot(data[4], color="skyblue")
sns.distplot(data[8], color="orange")
I just used my random sample.
I am just being a little lazy here, but all you need to do is a seaborn package.
There are much more options you can handle, so please read it more here [https://python-graph-gallery.com/]
Related
I have the following pandas Dataframe. alfa_value and beta_value are random, ndcg shall be the parameter deciding the color.
The question is: how do I do a heatmap of the pandas Dataframe?
You can use the code below to generate a heatmap. You have to adjust the bins to group your data (analyze the mean, the std, ...)
import pandas as pd
import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt
rng = np.random.default_rng(2022)
df = pd.DataFrame({'alfa_value': rng.integers(1000, 10000, 1000),
'beta_value': rng.random(1000),
'ndcg': rng.random(1000)})
out = df.pivot_table('ndcg', pd.cut(df['alfa_value'], bins=10),
pd.cut(df['beta_value'], bins=10), aggfunc='mean')
sns.heatmap(out)
plt.tight_layout()
plt.show()
In general, Seaborn's heatmap function is a nice way to color pandas' DataFrames based on their values. Good examples and descriptions can be found here.
Since you seem to want to color the row based on a different column, you are probably looking for something more like these answers.
So I am trying to plot correlation Matrix (already calculated) in python. the table is like below:
And I would like it to look like this:
I am using the Following code in python:
import seaborn as sn
import matplotlib.pyplot as plt
import pandas as pd
data =pd.read_excel('/Desktop/wetchimp_global/corr/correlation_matrix.xlsx')
df = pd.DataFrame(data)
print (df)
corrMatrix = data.corr()
print (corrMatrix)
sn.heatmap(corrMatrix, annot=True)
plt.show()
Note that, the matrix is ready and I don't want to calculate the correlation again! but I failed to do that. Any suggestions?
You are recalculating the correlation with the following line:
corrMatrix = data.corr()
You then go on to utilize this recalculated variable in the heatmap here:
sn.heatmap(corrMatrix, annot=True)
plt.show()
To resolve this, instead of passing in the corrMatrix value which is the recalculated value, pass the pure excel data data or df (as df is just a copy of data). Thus, all the code you should need is:
import seaborn as sn
import matplotlib.pyplot as plt
import pandas as pd
data =pd.read_excel('/Desktop/wetchimp_global/corr/correlation_matrix.xlsx')
sn.heatmap(data, annot=True)
plt.show()
Note that this assumes, however, that your data IS ready for the heatmap as you suggest. As we online do not have access to your data we cannot confirm that.
I have deleted to frist column (names) and add them later so the code is as below:
import seaborn as sn
import matplotlib.pyplot as plt
import pandas as pd
data =pd.read_excel('/Users/yousefalbuhaisi/Desktop/wetchimp_global/corr/correlation_matrix.xlsx')
fig, ax = plt.subplots(dpi=150)
y_axis_labels = ['CLC','GIEMS','GLWD','LPX_BERN','LPJ_WSL','LPJ_WHyME','SDGVM','DLEM','ORCHIDEE','CLM4ME']
sn.heatmap(data,yticklabels=y_axis_labels, annot=True)
plt.show()
and the results are:
I have a distribution that changes over time for which I would like to plot a violin plot for each time step side-by-side using seaborn. My initial attempt failed as violinplot cannot handle a np.ndarray for the y argument:
import numpy as np
import seaborn as sns
time = np.arange(0, 10)
samples = np.random.randn(10, 200)
ax = sns.violinplot(x=time, y=samples) # Exception: Data must be 1-dimensional
The seaborn documentation has an example for a vertical violinplot grouped by a categorical variable. However, it uses a DataFrame in long format.
Do I need to convert my time series into a DataFrame as well? If so, how do I achieve this?
A closer look at the documentation made me realize that omitting the x and y argument altogether leads to the data argument being interpreted in wide-form:
import numpy as np
import seaborn as sns
import matplotlib.pyplot as plt
samples = np.random.randn(20, 10)
ax = sns.violinplot(data=samples)
plt.show()
In the violin plot documentation it says that the input x and y parameters do not have to be a data frame, but they have a restriction of having the same dimension. In addition, the variable y that you created has 10 rows and 200 columns. This is detrimental when plotting the graphics and causes a dimension problem.
I tested it and this code has no problems when reading the python file.
import numpy as np
import seaborn as sns
import pandas as pd
time = np.arange(0, 200)
samples = np.random.randn(10, 200)
for sample in samples:
ax = sns.violinplot(x=time, y=sample)
You can then group the resulting graphs using this link:
https://python-graph-gallery.com/199-matplotlib-style-sheets/
If you want to convert your data into data frames it is also possible. You just need to use pandas.
example
import pandas as pd
x = [1,2,3,4]
df = pd.DataFrame(x)
I have tried to plot the data in order to achieve something like this:
But I could not and I just achieved this graph with plotly:
Here is the small sample of my data
Does anyone know how to achieve that graph?
Thanks in advance
You'll find a lot of good stuff on timeseries on plotly.ly/python. Still, I'd like to share some practical details that I find very useful:
organize your data in a pandas dataframe
set up a basic plotly structure using fig=go.Figure(go.Scatter())
Make your desired additions to that structure using fig.add_traces(go.Scatter())
Plot:
Code:
import plotly.graph_objects as go
import pandas as pd
import numpy as np
# random data or other data sources
np.random.seed(123)
observations = 200
timestep = np.arange(0, observations/10, 0.1)
dates = pd.date_range('1/1/2020', periods=observations)
val1 = np.sin(timestep)
val2=val1+np.random.uniform(low=-1, high=1, size=observations)#.tolist()
# organize data in a pandas dataframe
df= pd.DataFrame({'Timestep':timestep, 'Date':dates,
'Value_1':val1,
'Value_2':val2})
# Main plotly figure structure
fig = go.Figure([go.Scatter(x=df['Date'], y=df['Value_2'],
marker_color='black',
opacity=0.6,
name='Value 1')])
# One of many possible additions
fig.add_traces([go.Scatter(x=df['Date'], y=df['Value_1'],
marker_color='blue',
name='Value 2')])
# plot figure
fig.show()
I'm trying to present datatable collected from firewall logs in a histogram so that i would have one bar for each date in the file, and the number of occurences in a certain column stacked in the bar.
I looked into several examples here but they all seemed to be based on the fact that i would know what values there are in the particular column - and what i'm trying to achieve here is the way to present histogram without needing to know all possible fields.
In the example i have used protocol as the column:
#!/usr/bin/python
import pandas as pd
import numpy as np
import glob
import matplotlib.pyplot as plt
csvs = glob.glob("*log-export.csv")
dfs = [pd.read_csv(csv, sep="\xff", engine="python") for csv in csvs]
df_merged = pd.concat(dfs).fillna("")
data = df_merged[['date', 'proto']]
np_data = np.array(data)
plt.hist(np_data, stacked=True)
plt.show()
But this shows following diagram:
histogram
and i would like to accomplish something like this:
stacked
Any suggestions how to achieve this?
Setup
I had to make up data because you didn't provide any.
df = pd.DataFrame(dict(
Date=pd.date_range(end=pd.to_datetime('now'), periods=100, freq='H'),
Proto=np.random.choice('UDP TCP ICMP'.split(), 100, p=(.3, .5, .2))
))
Solution
Use pd.crosstab then plot
pd.crosstab(df.Date.dt.date, df.Proto).plot.bar(stacked=True)