**Gradient_file1_analogy.py**

**Gradient_file2_input-output.py**

**Gradient_file3_input-output2.py**

**Gradient_file4_why-partials.py**

**Gradient_file5_contour-lines-and-map.ipynb**

**Gradient_file6_surf-contour-plot.ipynb**

**Gradient_file7_missiles.py**

**Gradient_file8_fluid-flow.py**
