In an array xy=[x y], reduce array length by assigning average values of y based on a predefined range of x
2 views (last 30 days)
Show older comments
I have the x values in the range x=[x1 ... xn] and y values related to x through the function f as in y=f(x). Now I want to break down down the y array to a smaller array Y in that I first find all values related to x in the range x1>x>x0 and then calculate the mean of y values whose corresponding x's are in this range. Then I move on to the next range which is x2>x>x1 and calculate the mean of the corresponding y values and so on. At the end, this will look like converting a xy larger dataset to a smaller one, as shown in the picture. Since this is usually a really large dataset, I'd rather do this without a loop.
0 Comments
Answers (1)
Steven Lord
on 24 May 2023
Use findgroups or discretize to bin your X data into groups then use splitapply or groupsummary to calculate the @mean for each of those groups.
1 Comment
Dyuman Joshi
on 24 May 2023
This is neat. Though I found it difficult to implement the other pair - findgroups with groupsummary.
x = [(1:20)' randi(50,20,1)];
disp(x)
%Defining range of values
idx = [1 4 8 12 16 20];
out = discretize(x(:,1),idx);
splitapply(@mean, x(:,2), out)
See Also
Categories
Find more on Resizing and Reshaping Matrices in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!