DATA ANALYTICS REFERENCE DOCUMENT |
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Document Title: | Descriptive Statistics |
Document No.: | 1540829111 |
Author(s): | Rita Raher |
Contributor(s): |
REVISION HISTORY
Revision | Details of Modification(s) | Reason for modification | Date | By |
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0 | Draft release | Document description here | 2018/10/29 16:05 | Rita Raher |
Descriptive statistics describes the data. It is distinguished from inferential statistics, in that descriptive statistics aims to summarize a sample, rather than use the data to learn about the population that the sample of data is thought to represent. This generally means that descriptive statistics, unlike inferential statistics, is not developed on the basis of probability theory, and are frequently nonparametric statistics.
Some measures that are commonly used to describe a data set are measures of central tendency and measures of variability or dispersion. Measures of central tendency include the mean, median and mode, while measures of variability include the standard deviation (or variance), the minimum and maximum values of the variables, kurtosis and skewness.
Methods for visually presenting summary statistics include tables, charts, and graphical plots.
import pandas as pd df.describe()
In statistics, a central tendency (or measure of central tendency) is a central or typical value for a probability distribution. It may also be called a center or location of the distribution.
The most common measures of central tendency are:
import numpy as np # finding the mean np.mean(df) # mean of a column np.mean(df['col']) # finding the median np.median(df)
Graphical plots are interesting in that they pictorially convey a large amount of information in a concise way that allows for quick interpretation and understanding of the data.
The Box Plot