KDE Plot described as
Kernel Density Estimate
is used for visualizing the Probability Density of a continuous variable. It depicts the probability density at different values in a continuous variable. We can also plot a single graph for multiple samples which helps in more efficient data visualization. In this article, we will be using Iris Dataset and KDE Plot to visualize the insights of the dataset.
About the Iris Dataset
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- Attributes : Petal_Length (cm), Petal_Width (cm), Sepal_Length (cm), Sepal_Width(cm)
- Target : Iris_Virginica, Iris_Setosa, Iris_Vercicolor
- Number of Instances : 150
One-Dimensional KDE Plot :
We can visualize the probability distribution of a sample against a single continuous attribute.
Python3
# importing the required librariesfrom sklearn import datasetsimport pandas as pdimport seaborn as snsimport matplotlib.pyplot as plt%matplotlib inline# Setting up the Data Frameiris = datasets.load_iris()iris_df = pd.DataFrame(iris.data, columns=['Sepal_Length', 'Sepal_Width', 'Patal_Length', 'Petal_Width'])iris_df['Target'] = iris.targetiris_df['Target'].replace([0], 'Iris_Setosa', inplace=True)iris_df['Target'].replace([1], 'Iris_Vercicolor', inplace=True)iris_df['Target'].replace([2], 'Iris_Virginica', inplace=True)# Plotting the KDE Plotsns.kdeplot(iris_df.loc[(iris_df['Target']=='Iris_Virginica'), 'Sepal_Length'], color='b', shade=True, label='Iris_Virginica')# Setting the X and Y Labelplt.xlabel('Sepal Length')plt.ylabel('Probability Density') |
Output:
We can also visualize the probability distribution of multiple samples in a single plot.
Python3
# Plotting the KDE Plotsns.kdeplot(iris_df.loc[(iris_df['Target']=='Iris_Setosa'), 'Sepal_Length'], color='r', shade=True, label='Iris_Setosa')sns.kdeplot(iris_df.loc[(iris_df['Target']=='Iris_Virginica'), 'Sepal_Length'], color='b', shade=True, label='Iris_Virginica')plt.xlabel('Sepal Length')plt.ylabel('Probability Density') |
Output:
Two-Dimensional KDE Plot :
We can visualize the probability distribution of a sample against multiple continuous attributes.
Python3
# Setting up the samplesiris_setosa = iris_df.query("Target=='Iris_Setosa'")iris_virginica = iris_df.query("Target=='Iris_Virginica'")# Plotting the KDE Plotsns.kdeplot(iris_setosa['Sepal_Length'], iris_setosa['Sepal_Width'], color='r', shade=True, label='Iris_Setosa', cmap="Reds", shade_lowest=False) |
Output:
We can also visualize the probability distribution of multiple samples in a single plot.
Python3
# Plotting the KDE Plotsns.kdeplot(iris_setosa['Sepal_Length'], iris_setosa['Sepal_Width'], color='r', shade=True, label='Iris_Setosa', cmap="Reds", shade_lowest=False)sns.kdeplot(iris_virginica['Sepal_Length'], iris_virginica['Sepal_Width'], color='b', shade=True, label='Iris_Virginica', cmap="Blues", shade_lowest=False) |
Output:
