Distance between two nodes

Hey Guys,

I'm kinda stuck trying to figure out a way to use a for loop to find the distance between a 7x2 matrix I have.

nodes=[0,0;2,0;2,3;3.5,1.5;5,0;5,3;7,0]

0 0

2 0

2 3

3.5 1.5

5 0

5 3

7 0

I want to try and make a script that will check check the distance between every node and if the distance is less than or equal to sqrt(13) plot a line between the two points.

I was thinking

for r=nodes(1):nodes(end)

dis=%not really sure how to input it so that it's the (x1-x2)^2 +(y1-y2)^2 for the distance between all the nodes

if dis<=13

plot([xi, xf],[yi,yf])

else %no sure how to continue the loop

end

end

I did this before with gplot, but I can't use it for this next part

If you guys could help me set this up it would be really appreciated thanks!!