## Time sseries analysis with python

##### Categories

Introduction :

Time series analysis is a statistical technique that deals with time series data, or data that is indexed by time. It is used to analyze and forecast trends and patterns in data over time. Python is a popular programming language for time series analysis due to its simplicity and powerful libraries. In this article, we will explore how to perform time series analysis in Python and how it can be used to gain insights from your data.

Trends and Seasonality:

Finding trends and seasonality in time series data is an important part of time series analysis. Trends refer to the long-term changes in the data, while seasonality refers to the periodic fluctuations in the data. Python provides several libraries for analyzing trends and seasonality in time series data, including Pandas and Statsmodels.To find trends and seasonality in time series data using Python, you can follow these steps:

1. **Load the Data:** Load the time series data into a Pandas DataFrame.

2. **Visualize the Data:** Plot the time series data to visualize any trends or seasonality.

3. **Decompose the Data:** Use the Statsmodels library to decompose the time series data into its trend, seasonal, and residual components.

4. **Test for Stationarity:** Use statistical tests to determine if the time series data is stationary or non-stationary.

5. **Remove Trends and Seasonality:** If the time series data is non-stationary, remove the trends and seasonality using techniques such as differencing or detrending.For more information on how to find trends and seasonality in time series data using Python, check out these resources:

– [Time Series Analysis in Python – A Comprehensive Guide with Examples](https://www.machinelearningplus.com/time-series/time-series-analysis-python/)- [A Guide to Time Series Analysis in Python | Built In](https://builtin.com/data-science/time-series-python)- [Tutorial: Time Series Analysis with Pandas – Dataquest](https://www.dataquest.io/blog/tutorial-time-series-analysis-with-pandas/)”

Here’s an example code using Tesla stock price:

``````import pandas as pd
import matplotlib.pyplot as plt
from statsmodels.tsa.seasonal import seasonal_decompose

# Visualize the Data
plt.plot(tesla)
plt.title('Tesla Stock Price')
plt.xlabel('Date')
plt.ylabel('Price')
plt.show()

# Decompose the Data
result = seasonal_decompose(tesla, model='multiplicative')

# Plot the Decomposed Data
result.plot()
plt.show()

# Test for Stationarity

print(f'p-value: {result}')
print(f'Critical Values: {result}')

# Remove Trends and Seasonality
tesla_diff = tesla.diff().dropna()

# Visualize the Differenced Data
plt.plot(tesla_diff)
plt.title('Differenced Tesla Stock Price')
plt.xlabel('Date')
plt.ylabel('Price')
plt.show()``````

This code loads the Tesla stock price data into a Pandas DataFrame, visualizes the data using Matplotlib, decomposes the data into its trend, seasonal, and residual components using Statsmodels, tests for stationarity using the Augmented Dickey-Fuller test, and removes trends and seasonality using differencing.

You can replace `tesla_stock_price.csv` with your own time series data file.

Moving average is a commonly used method for finding trends in time series data. It involves calculating the average of a rolling window of data points over time.Here’s an example code using moving average to find trends in Tesla stock price:

“`pythonimport pandas as pdimport matplotlib.pyplot as plt# Load the Datatesla = pd.read_csv(‘tesla_stock_price.csv’, parse_dates=[‘Date’], index_col=’Date’)# Calculate the Moving Averagerolling_mean = tesla[‘Close’].rolling(window=30).mean()# Visualize the Data and Moving Averageplt.plot(tesla)plt.plot(rolling_mean)plt.title(‘Tesla Stock Price’)plt.xlabel(‘Date’)plt.ylabel(‘Price’)plt.legend([‘Price’, ‘Moving Average’])plt.show()“`

This code loads the Tesla stock price data into a Pandas DataFrame, calculates the moving average using a rolling window of 30 data points, and visualizes the data and moving average using Matplotlib.You can replace `tesla_stock_price.csv` with your own time series data file and adjust the window size as needed.