What is the meaning of p(1, :) in the following lines?

p = thermalModelT.Mesh.Nodes;
nodesLeftEnd  = find(p(1,:) < -1.5+eps);
nodeCenter = nodesLeftEnd(p(2,nodesLeftEnd) < eps);
nodeOuter = nodesLeftEnd(p(2,nodesLeftEnd) > 0.2-eps);

In the above lines, what does it mean by p(1,:) and p(2,nodesLeftEnd)?

[Stephen23]

"what does it mean by p(1,:) and p(2,nodesLeftEnd)?"

Very basic MATLAB concepts, such as indexing into arrays, is explained in the introductory tutorials:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

Answer 1

[Alan Stevens]

It refers to the first row and all columns of matrix p.

So find(p(1,:) < -1.5+eps); means look through all the columns of the first row of p and find which ones satisfy the condition that they are less than -1.5+eps.