# Python SciPy Tutorial for Beginners

Python consists of SciPy, which is an **open-source library**. The library is distributed under a **BSD license**.

Python Scipy is meant to **compute** the **scientific**, **mathematical**, and **engineering problems**. It is **user-friendly**. It is a useful tool for **numerical integration** and **optimization**. SciPy is pronounced as **Sigh Pi**. SciPy is a **scientific library**.

Let us learn more about Python Scipy through this TechVidvan Python Tutorial.

### Python SCiPy Tutorial

SciPy is the **base library**. It is built on top of **NumPy extension**. There is no need to import NumPy if we have **SciPy **imported. It includes working on **arrays**.

The SciPy is compatible with the **N-dimensional array object** of **NumPy**. It consists of **code** for the operation of NumPy functions. SciPy and NumPy together is the best choice for **scientific operations**.

### Prerequisite

The two essential **prerequisites** for SciPy are **Python** and **Mathematics**. As SciPy is built on **python language**, basic learning about Python is a **requirement**.

Also, as SciPy is for carrying out **mathematical calculations**, knowledge of mathematics is necessary for **output verification** and **understanding**.

### Uses of SciPy

SciPy is a very useful scientific library for **mathematical** and **scientific calculations**. It consists of a **wide range** of **mathematical algorithms** to work with. It helps **create useful programs**. SciPy has significant additions being an **open-source library**. It has a variety of **modules**, which is a very beneficial source for **scientific calculations**.

### SciPy Sub-packages

SciPy consists of a variety of packages to carry out a **range** **of functionalities**. It has packages for **specific requirements**. It consists of more than **15 packages** for carrying out the operations.

SciPy has a dedicated package for **statistical functions**, **linear algebra**, **clustering of the data**, **image and signal processing**, for **matrices**, for **integration** and **differentiation**, etc.

Here are some of the examples:

**linalg –**It is a package dedicated to carrying out**linear algebra operations**.**cluster –**It is a package for conducting**clustering algorithms****constants –**it works with**constant values**.**integrate –**it is to perform the**differentiation**and**integration**functions**ndimage –**it is for**image processing****signal –**it is a package for**signal processing****stats –**it works for**statistical functions****io –**it is meant to work for**input**and**output**operations.**fftpack –**it is meant for**Fourier transform**operation.**odr –**it is for**orthogonal distance regression**.**special –**it is a module for**special functions**.**sparse –**it is meant to work with**sparse matrices**.**spatial –**it is meant to work with**spatial data**and**algorithms**.**weaves –**it is a tool meant for**writing purposes**.**interpolation –**it is meant for**interpolation operations**.**optimize –**it is a tool for the**optimization**of the**arrays**.

### NumPy vs SciPy

Scipy is an **open-source library**, hence its functionality keeps on growing. Numpy on the other hand has **lesser functionality**.

The difference also lies in the **array object**.

The arrays in NumPy are **homogenous** while this constraint **does not exist** in SciPy. Scipy builds on Numpy and hence both the libraries are **interrelated**.

### File Input Output Package

SciPy has **capabilities** to work along with other files. It has the **input/output package** which enables us to **access** other **file formats**.

With this package, we can work with **Matlab**, **Arff**, **Wave**, **Matrix** **Market**, **IDL**, **NetCDF,** **TXT, CSV,** and **binary format files**.

We take an example of Matlab file format,

import numpy as np from scipy import io as sio array = np.zeros((5, 5)) sio.savemat('example.mat', {'ar': array}) data = sio.loadmat('example.mat', struct_as_record=True) data['ar']

**Output**

[0., 0., 0., 0., 0.],

[0., 0., 0., 0., 0.],

[0., 0., 0., 0., 0.],

[0., 0., 0., 0., 0.]])

### Special Function Package

SciPy consists of a **scipy.special package** to work with **complex mathematical** and **physics calculations**. It consists of a **wide range** of **functions** for these calculations. It can deal with **logarithmic**, **exponential, permutations** and **combinations, parabolic** and **exponential problems**. It has functions for **cube roots**, **lambert, beta, gamma, Bessel,** and **hypergeometry.**

All these functions follow the **broadcasting** and **array looping regulations**.

We can call the functions as follows:

**#log sum function : ****scipy.special.logsumexp(x)**

**#bessel function : ****scipy.special.jn()**

**#cube root function : ****scipy.special.cbrt(x)**

### Exponential Function

from scipy.special import exp10 # exp function exp = exp10([1,10]) print(exp)

**Output**

### Permutations and Combination

from scipy.special import comb,perm # combinations com = comb(3, 4, exact = False, repetition=True) print(com) # permutation per = perm(3, 2, exact = True) print(per)

**Output**

6

### Linear Algebra with SciPy

Scipy consists of** scipy.linalg** whose working based on **BLAS** and **LAPACK**. But it has a **better performance** and **speed of calculations**.

The functions accept **two-dimensional** **array input** and **output** is also a two-dimensional array.

from scipy import linalg import numpy as np a = np.array([ [5,7], [10,20] ]) # det() function linalg.det(a )

**Output**

Similarly, we can calculate for **inverse matrices**, **eigenvalues,** and **vectors. **It consists of all **basic** and **complex linear functions**.

### Discrete Fourier Transform

Scipy has a package for **DFT,scipy.fftpack**. We perform DFT for conversion of **spatial data** into **frequency data**. We also have functions for **Fast Fourier Transform**.

FFT is useful when working with **multidimensional arrays**.

The **frequency transformation** helps determine the **signals** and **wavelengths**.

from matplotlib import pyplot as plt import numpy as np fre = 2 fre_samp = 10 t = np.linspace(0, 2, 2 * fre_samp, endpoint = False ) a = np.sin(fre * 2 * np.pi * t) figure, axis = plt.subplots() axis.plot(t, a) axis.set_xlabel ('Time (s)') axis.set_ylabel ('Signal amplitude') plt.show()

**Output**

### Optimization and Fit in SciPy

For optimization in SciPy we have the **scipy.optimize module**. It is a really tool for **optimizing** the final outputs. It can be useful when we want to **minimize curves**, **root** and **scalar** **values**.

import matplotlib.pyplot as plt from scipy import optimize import numpy as np def function(a): return a*1 + 5 * np.sin(a) plt.plot(a, function(a)) plt.show() optimize.fmin_bfgs(function, 0)

**Output**

Current function value: -6.671134

Iterations: 4

Function evaluations: 18

Gradient evaluations: 6

array([-1.77215427])

One of the most basic optimization algorithms in Python scipy tutorial is the **Nelder Mead algorithm. **It is one of the most basic method for **minimization** of **function**. We can select it using the **method argument**.

It has a drawback for **gradient evaluations** as it has a **slow performance**.

import numpy as np from scipy.optimize import minimize #define function f(x) def f(x): return (2*(1 + x[0])**2) optimize.minimize(f, [2, 1], method="Nelder-Mead")

**Output**

[-1. , 1.72509766],

[-1. , 1.72501221]]), array([0., 0., 0.]))

fun: 0.0

message: ‘Optimization terminated successfully.’

nfev: 159

nit: 73

status: 0

success: True

x: array([-1. , 1.725])

### Image Processing

SciPy consists of the **scipy.ndimage** **module** for **image processing**. It is a very useful package for processing **n-dimensional images**. It has various **manipulation** **functions** like **filtering**, **rotate**, **crop**, **display**, **classification** and **feature extraction**.

We can use the **MISC** package to **access images** and **perform operations**.

from scipy import misc from matplotlib import pyplot as plt import numpy as np panda = misc.face() #plot image plt.imshow( panda ) plt.show()

**Output**

### Summary

Finally, we come to the end of the Python SciPy tutorial. SciPy is a very important **open-source package** in Python. It is one of the most basic packages for carrying out **python operations**.

SciPy is **easy to understand** and **consists** of **huge functionality**. It is **user-friendly** while carrying out **mathematical** and **scientific analysis**. It has **extended functionality** because of its **sub-packages**.