2D interpolation (interp2d, griddata) in SciPy - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is 2D interpolation in data science?

2D interpolation is a method to estimate unknown values on a two-dimensional grid using known data points. It helps fill gaps or smooth data in a surface or map.

beginner

What does the scipy function interp2d do?

interp2d creates a function that estimates values on a 2D grid by interpolating between known points. It works well for regularly spaced data.

intermediate

How does griddata differ from interp2d?

griddata can interpolate scattered data points that are irregularly spaced, while interp2d expects data on a regular grid.

intermediate

What interpolation methods can griddata use?

griddata supports methods like 'nearest' (closest point), 'linear' (triangular interpolation), and 'cubic' (smooth surface).

beginner

Why might you choose griddata over interp2d?

Choose griddata when your data points are scattered and not on a regular grid. It handles irregular spacing better.

Which scipy function is best for interpolating data on a regular 2D grid?

A interp2d

B griddata

C curve_fit

D fft

interp2d is designed for regular 2D grids, while griddata handles scattered points.

What interpolation method in griddata creates the smoothest surface?

A linear

B cubic

C nearest

D constant

The 'cubic' method produces a smooth surface by fitting cubic polynomials.

If your data points are scattered irregularly, which function should you use?

A polyfit

B interp2d

C griddata

D interp1d

griddata is suitable for scattered data points.

Which of these is NOT a valid interpolation method for griddata?

A exponential

B linear

C nearest

D cubic

'exponential' is not a supported method in griddata.

What does 2D interpolation help you do?

A Convert 2D data to 1D

B Sort data points alphabetically

C Calculate the mean of a dataset

D Estimate missing values on a 2D surface

2D interpolation estimates unknown values between known points on a surface.

Explain the difference between interp2d and griddata in your own words.

Think about how your data points are arranged.

Describe a real-life situation where 2D interpolation would be useful.

Imagine you have temperature readings from weather stations.