Python Reading

• Read the introduction entitled What is NumPy?

Key Ideas

• NumPy is Python library written in C to provide fast numerical methods for scientific computation.
• NumPy enables Python users to use a data structure called an array. You can conceptualize an array as an efficient implementation of a list.
• Today we will learn about 1-D (one dimensional) arrays. However, Python arrays can contain any number of dimensions.

Getting Started

• Install NumPy on your machine:
  • Windows: python -m pip install numpy
  • Mac: pip3 install --user numpy

In-Class Activity

• One way to gain insight into numeric data is to calculate its mean and standard deviation. More information.
• Sometimes it is useful to sort numeric data into either ascending or descending order. Why?
• Download demo.py and conduct experiments until you fully understand it.
• Can you explain how the sort function works?
• The sort function does not return anything. Why does the shoulder_heights array in the main program change?
• Can you modify the sort function so that it sorts the data into descending order?
• The NumPy module includes a sort function. Can you find the relevant documentation and then use it?
• What are other useful things you might want to do with a 1-D array?

Active Learning

• Work through tutorial1.py.

Optional Alternative NumPy Installation for Windows Users

Enter the second instruction in the MS-DOS command prompt, from the same directory where the module was downloaded.

• Download numpy, choosing the version in the next instruction.
• python -m pip install numpy-1.13.3+mkl-cp36-cp36m-win32.whl