How to do distance formula

Im trying to find the distance between 2 points on a truss and I have the length and the x and y of the nodes on the truss but what code in matlab would make this work.

I know

d = sqtrt((x2-x1)^2+(y2-y1)^2) ; 

But how would I apply it to an array on a truss

with x being the nodes and e being the edges or lines that connect nodes

X = [0  0
     1  0
     2  0
     2  1
     1  1
     0  1
     ];
e =  [1  2
          2  3
          3  4
          4  5
          5  6
          6  1
          2  4
          3  5
          1  5
          2  6];

I just dont seem to get how to put these two together and make a distance formula that works. The lengths of these points are the outside lengths are 1 m and the cross section lengths are the sqrt of 2(these inside ones being from 1 to 5, 6 to 2, 4 to 2, and 5 to 3.

[Rik]

Which distance do you want to calculate? Your array X encodes x and y coordinates, so that is what you should end up using, but first you need to be able to tell what exactly you want to know.

[Kaden Bauernfeind]

Thats kinda the problem. I need to know the length of each section of the truss and be abble to put them into an array to use to find how the breaking point occurs.

[Rik]

So you need the length of each section? I would suggest looping through the rows of your e array. Those are indices to your X array, which contain the x and y coordinates.

[Kaden Bauernfeind]

ok and how would I go about that I'm really not the best with Matlab. and thank you for the help

[Rik]

Which part is causing you trouble? Writing a loop? Indexing? Try something and I will help you get to the result.

[Kaden Bauernfeind]

writing a loop

I under stand that it would be a for loop but how I would apply the i is kinda what confuses me

example

for i = 1:n

i know thats how its formated I just dont know what the 1:n means.

[Rik]

If you have trouble with Matlab basics you may consider doing the Onramp tutorial (which is provided for free by Mathworks). That should help with tasks like this.

Answer 1

[Matt J]

A=pdist2(X,X);

distances = A( sub2ind(size(A) ,e(:,1),e(:,2) )  )