Block 17: Aggregations & Statistics
Summarize arrays with aggregate functions along any axis.
Concepts
- sum(), mean(), std(), var(), min(), max()
- axis=0 (column-wise), axis=1 (row-wise)
- np.median(), np.percentile()
- np.cumsum(), np.diff()
Code Examples
See exercise below.
Exercise
For a 4×5 random matrix: compute max per row, min per column, overall std. Given daily temperatures for 4 weeks (4×7), compute weekly averages.
Homework
Explain the difference between axis=0 and axis=1 with a diagram or example.