html_theme_options:

authors:

- name: Thomas J. Sargent

url: https://www.tomsargent.com/

url: http://www.tomsargent.com/

- name: John Stachurski

url: https://johnstachurski.net/

dark_logo: quantecon-logo-transparent.png

For this we need to use libraries for working with arrays.

For Python, the most important matrix and array processing library is

[NumPy](https://www.numpy.org/) library.

[NumPy](https://numpy.org/) library.

For example, let's build a NumPy array with 100 elements

### SciPy

The [SciPy](https://www.scipy.org) library is built on top of NumPy and provides additional functionality.

The [SciPy](https://scipy.org/) library is built on top of NumPy and provides additional functionality.

(tuple_unpacking_example)=

For example, let's calculate $\int_{-2}^2 \phi(z) dz$ where $\phi$ is the standard normal density.

```{index} single: Python; SciPy

```

Much of this functionality is also available in [SciPy](https://www.scipy.org/), a collection of modules that are built on top of NumPy.

Much of this functionality is also available in [SciPy](https://scipy.org/), a collection of modules that are built on top of NumPy.

We'll cover the SciPy versions in more detail {doc}`soon <scipy>`.

:scale: 100

```

Just as [NumPy](https://www.numpy.org/) provides the basic array data type plus core array operations, pandas

Just as [NumPy](https://numpy.org/) provides the basic array data type plus core array operations, pandas

1. defines fundamental structures for working with data and

1. endows them with methods that facilitate operations such as

Python makes it straightforward to query online databases programmatically.

An important database for economists is [FRED](https://research.stlouisfed.org/fred2/) --- a vast collection of time series data maintained by the St. Louis Fed.

An important database for economists is [FRED](https://fred.stlouisfed.org/) --- a vast collection of time series data maintained by the St. Louis Fed.

For example, suppose that we are interested in the [unemployment rate](https://research.stlouisfed.org/fred2/series/UNRATE).

For example, suppose that we are interested in the [unemployment rate](https://fred.stlouisfed.org/series/UNRATE).

(To download the data as a csv, click on the top right `Download` and select the `CSV (data)` option).

## Overview

[SciPy](https://www.scipy.org) builds on top of NumPy to provide common tools for scientific programming such as

[SciPy](https://scipy.org/) builds on top of NumPy to provide common tools for scientific programming such as

* [linear algebra](https://docs.scipy.org/doc/scipy/reference/linalg.html)

* [numerical integration](https://docs.scipy.org/doc/scipy/reference/integrate.html)