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Favor Molyn
Favor Molyn

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Understanding Your Data: The Essentials of Exploratory Data Analysis

Introduction
In the data-driven world, the journey from raw data to insightful conclusions begins with a crucial step: Exploratory Data Analysis (EDA). It is not a mere preparation for modeling but a method that can help you to see what is hidden in your data and can explain the main trends, patterns, and outliers. EDA makes a messy looking set of data look orderly and presentable and enable the decision maker to make the right decision confidently.
Exploratory Data Analysis (EDA)
Exploratory Data Analysis is a statistical method that allows to get an understanding of the data structure. It refers to an approach of providing an overview of the qualities of the data, which can be done graphically. As the name suggests, EDA gives a visual representation of what the actual data is and therefore, the analyst can be in a position to detect some outliers and check assumptions before proceeding to other rigorous analyses.

EDA incorporates several aspects as follows:
Data Cleaning
The first key procedure in EDA is to check if your data is erroneous or not. This includes dealing with missing data, range and consistency errors as well as outliers. The quality of data determines the quality of analysis that will be produced.
To preview the dataset before cleaning the python code is:

df.shape
df.info()
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Data Visualization
Visualization is an essential component of EDA as a practice. Histograms, scatter plots and the box plots are some of the tools that will assist in displaying the data density, the correlation between variables and identification of trends a period. Visuals enable one to be able to have a good picture of what is being presented hence enabling one to be able to come up with better conclusions. In python, libraries such as matplotlib and seaborn.
The following is a code to import these libraries in python:

import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
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Descriptive Statistics
Measures of central tendency such as mean, median, mode, measures of dispersion such as standard deviation, and percentile provide a quick information about the distribution and dispersion of the data respectively. In descriptive statistics, one prepares the ground for the actual understanding of the nature of the data available in terms of their structure.
For statistical summary this code gives the mean, median, measures of dispersion and the distribution.

df.describe()
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Identifying Patterns and Relationships
The details gathered during EDA can be analyzed using various statistical tools such as correlation analysis, distribution analysis, etc., and visual tools such as graphs and heatmaps. These insights are important to avoid building models which do not stand for reality as it is experienced.
Conclusion
Exploratory Data Analysis is not just a pre-analysis stage; it is a multistage process that opens the door to data analysis. When you overemphasize the analysis of your data, you are able to discover trends that may not be obvious, identify problems that may arise in the future, and get to know the factors involved in the study area very well. It is critical to master EDA for anyone who wants to understand the different aspects of data and make correct and meaningful conclusions. Over time, as we work through EDA, you will discover that the data is also ‘talking’ and full of insights.

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