Interpolating a function that is constant over some parts of its domain?
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Jonathan Hawkins
on 12 Jun 2017
Commented: Jonathan Hawkins
on 13 Jun 2017
I'm trying to write code that will linearly interpolate samples from a generic real-valued function. Interp1 seems to break if the function is constant over any part of its domain, and unfortunately for me this is an extremely common use case - as a simple function:
{0, if x<0
f(x) = {x, if 0<=x<=1
{1, otherwise
It seems like interp1([0, 0, 1, 1], [-10,0,1,10], x) ought to return this function (for x \in [-10,10]), but instead I get the error that "The grid vectors must contain unique points."
Is there another interpolation function that doesn't break when you feed it functions that are sometimes constant?
1 Comment
Stephen23
on 12 Jun 2017
vq = interp1(x,v,xq)
where x is the independent variable. You have the x and v swapped around.
Accepted Answer
David Goodmanson
on 12 Jun 2017
Edited: David Goodmanson
on 12 Jun 2017
Hi Jonathan,
just swap inputs,
interp1([-10,0,1,10], [0,0,1,1], x)
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