interp1d for 1D interpolation in SciPy - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is interp1d in SciPy?

interp1d is a function in SciPy that creates a callable function to perform 1-dimensional interpolation between data points.

beginner

What inputs does interp1d require?

It requires two arrays: x (known data points) and y (values at those points). It returns a function to estimate values between these points.

intermediate

What does the kind parameter in interp1d control?

The kind parameter controls the type of interpolation method, such as 'linear' (default), 'nearest', 'cubic', or 'quadratic'.

beginner

How do you use the function returned by interp1d?

After creating the interpolation function, call it with new x values to get interpolated y values.

intermediate

What happens if you try to interpolate outside the original x range?

By default, interp1d raises an error if you try to interpolate outside the original x range. You can allow extrapolation by setting fill_value="extrapolate".

What does interp1d return?

A A new array of interpolated values

B A function to estimate values between known points

C A plot of the data points

D A matrix of distances

interp1d returns a function that you can call with new x-values to get interpolated y-values.

Which parameter controls the interpolation method in interp1d?

A kind

B type

C mode

D method

The kind parameter sets the interpolation type like 'linear' or 'cubic'.

What happens if you try to interpolate outside the original x range without setting fill_value?

A Raises an error

B Returns NaN

C Returns zero

D Automatically extrapolates

By default, interp1d raises an error if you try to interpolate outside the original x range.

Which of these is NOT a valid kind option in interp1d?

A linear

B nearest

C logarithmic

D cubic

logarithmic is not a valid interpolation kind in interp1d.

If you have x = [1, 2, 3] and y = [2, 4, 6], what is the interpolated value at x=2.5 using linear interpolation?

A 6.0

B 4.5

C 3.5

D 5.0

Linear interpolation between points (2,4) and (3,6) at 2.5 is 4 + (6-4)*0.5 = 5.0, so correct answer is A.

Explain how to create and use a 1D interpolation function with interp1d.

Think about the inputs and outputs of interp1d.

Describe what happens if you try to interpolate outside the original data range and how to handle it.

Consider the parameter that controls out-of-range behavior.