# Calculating distance between two points from a matrix in 2d and 3d

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lisa Liang on 21 Jul 2020
Commented: paul harder on 8 Apr 2021
Hi everyone!
I am new to MatLab and coding. I have a set of points in x and y coordinates, and they are sorted in a 701*14 matrix called 'rawdata'. The first two column are x and y coordinate for point#1 and the next two are the x and y coordinates for point#2 (as shown in screenshot). I want to calculate the distance between point#1 and point#2 for each row and have the resulted distance in matrix. I think I'd calculate distance by sqrt((x2 - x1) ^ 2 + (y2 - y1) ^ 2) in 2d or sqrt((x2 - x1) ^ 2 + (y2 - y1) ^ 2 + (z2 - z1) ^ 2)in 3d? But how do I write in a formatt that matlab can read and calculate?
Sorry I am a coding newb. And thank you very much for your help in advance! waqas on 21 Jul 2020
This would be the implementation of your formula. But, NaN would be a problem for you since 3rd and 4th columns are NaN and would make the output distance NaN too.
dist = sqrt(((A(:,3)-A(:,1)).^2 + (A(:,4)-A(:,1)).^2))
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paul harder on 8 Apr 2021
just to clarify a minor typo, the last 1 should be a 2
dist = sqrt(((A(:,3)-A(:,1)).^2 + (A(:,4)-A(:,2)).^2))