 Statistical functions are often used in software development, especially in data analytics and machine learning. For PHP developers, the Statistics PHP package provides various statistical functions for mathematical analysis of numeric data. In this article, we will discuss the key features of the Statistics PHP package and how to use them in PHP code.

## Statistics PHP package

The Statistics PHP package is a PHP package that provides various statistical functions for mathematical analysis of numeric data. The package collects some useful statistical functions such as mean, mode, median, range, quantiles, first quartile, third quartile, frequency table (cumulative, relative), standard deviation (population and sample), variance (population and sample), geometric mean, harmonic mean, correlation, covariance, and linear regression.

The Statistics PHP package is inspired by the Python statistics module and can be installed using Composer, a package manager for PHP.

Installation To install the Statistics PHP package, use the following command:

`composer require hi-folks/statistics`

This command will download and install the package and its dependencies in the project.

Usage After installing the Statistics PHP package, developers can use its functions in their PHP code by importing the Stat class. Here are some of the key functions of the Stat class:

1. `mean()` – calculates the arithmetic mean or “average” of data
2. `median()` – calculates the median or “middle value” of data
3. `medianLow()` – calculates the low median of data
4. `medianHigh()` – calculates the high median of data
5. `mode()` – calculates the single mode (most common value) of discrete or nominal data
6. `multimode()` – returns a list of modes (most common values) of discrete or nominal data
7. `quantiles()` – cuts points dividing the range of a probability distribution into continuous intervals with equal probabilities
8. `thirdQuartile()` – calculates the 3rd quartile, which is the value at which 75 percent of the data is below it
9. `firstQuartile()` – calculates the first quartile, which is the value at which 25 percent of the data is below it
10. `pstdev()` – calculates the population standard deviation
11. `stdev()` – calculates the sample standard deviation
12. `pvariance()` – calculates the variance for a population
13. `variance()` – calculates the variance for a sample
14. `geometricMean()` – calculates the geometric mean
15. `harmonicMean()` – calculates the harmonic mean
16. `correlation()` – calculates the Pearson’s correlation coefficient for two inputs
17. `covariance()` – calculates the sample covariance of two inputs
18. `linearRegression()` – returns the slope and intercept of simple linear regression parameters estimated using ordinary least squares

Here are some sample codes to illustrate the use of a few of the functions:

``````use HiFolks\Statistics\Stat;

// calculate the mean
\$mean = Stat::mean([1, 2, 3, 4, 4]);
// \$mean = 2.8

// calculate the geometric mean
\$geometricMean = Stat::geometricMean([54, 24, 36], 1);
// \$geometricMean = 36.0

// calculate the median
\$median = Stat::median([1, 3, 5]);
// \$median = 3

// calculate the low median
\$medianLow = Stat::medianLow([1, 3, 5]);
// \$medianLow = 3``````

## Conclusion

The package provides a comprehensive set of functions for calculating mathematical statistics of numeric data. It is easy to use and has clear documentation, making it a great tool for developers who need to perform statistical analysis in their PHP projects. This package is also inspired by the Python statistics module, making it familiar to those who have experience in Python.

Whether you are a developer building a complex application that requires statistical analysis or just someone who needs to perform basic statistical calculations, the Hi-Folks/statistics package has got you covered.

With features such as mean, mode, median, range, quantiles, standard deviation, variance, geometric mean, harmonic mean, correlation, covariance, and linear regression, this package offers a wide range of statistical functions that you can use to analyze data.

Overall, the Hi-Folks/statistics PHP package is a great addition to any PHP developer’s toolbox. Its ease of use, comprehensive set of functions, and clear documentation make it an excellent choice for anyone who needs to perform statistical analysis in their PHP projects.