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

To install Anaconda

This includes Numpy and more data science modules we will also use later.

🐍 Installing NumPy with Anaconda (Mac & Windows)

>>>>>>>>These instructions were generated by ChatGPT. We can try this out together in class and see if there are problems.*

✅ Why use Anaconda?

Anaconda is a Python distribution that already includes NumPy and many other useful libraries—so students usually don’t need to install anything extra.

⬇️ Step 1: Download Anaconda

1. Go to the official website:
   https://www.anaconda.com/download
2. Download:
   • Windows → 64-bit Graphical Installer
   • Mac → Choose the correct version (Intel or Apple Silicon)
     
     

To NOT create an account...

✅ Easiest workaround (no account required)

Use the direct download page instead of the main landing page:

👉 Go to: https://repo.anaconda.com/archive/

From there:

1. Scroll to the version you want (usually the latest is fine)
2. Download the installer directly:
   • Windows: .exe
   • Mac: .pkg
3. Run the installer normally

This completely bypasses any login/signup prompt.

⚙️ Step 2: Install Anaconda

💻 Windows

1. Double-click the downloaded installer
2. Click Next → Agree → Next
3. Choose Just Me (recommended)
4. Leave settings as default
5. Click Install

🍎 Mac

1. Open the downloaded .pkg file (easier to use than .sh)
2. Click through the installer steps
3. Install with default settings

Apple Silicon Macs (M1, M2, M3, etc.) Most newer Macs (≈ 2020+)

Look for: arm64 or Apple Silicon

Intel Macs Older Macs (pre-2020)

Look for: x86_64

▶️ Step 3: Open Anaconda Navigator

After installation:

• Open Anaconda Navigator (search for it like any app)
• This is your control panel for Python tools

🧪 Step 4: Launch Python

You have two easy options:

Option A (Recommended for beginners)

Launch:

• Jupyter Notebook
  or
• JupyterLab

Click Launch, then open a new Python notebook.

Option B (If you want something like IDLE)

Launch:

• Spyder (comes with Anaconda, similar to IDLE but more powerful)

🔍 Step 5: Test NumPy

In your notebook or Spyder, type:

If you see:

🎉 NumPy is already installed and working!

⚠️ Troubleshooting

“It won’t open”

• Restart your computer after installing

“Navigator is slow”

• Be patient on first launch—it can take a minute

“Still want to use IDLE?”

Anaconda uses its own Python. If students open IDLE from their system Python, NumPy might not be there.

👉 Best fix: Use Jupyter or Spyder instead.

🧠 Teacher Tips

• This approach avoids most install problems from pip
• All students get the same environment
• Great for data science and future lessons

* >>>>>>>> End of ChatGPT instructions

To install only Numpy:

• 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