Manually assign nodal/elemental values

I am totally new to FreeFEM and I want to change some lines from a specific code. I need some help. Thank you in advance.


real L = 4;
real W = 1;
real v = 0.5;
border b1(t = -0.025W, 0.025W){x = 0.5L; y = t; label = loaded;}
border b2(t = 0.025
W, 0.5W){x = 0.5L; y = t; label = free; }
border b3(t = 0.5L, -0.5L){x = t; y = 0.5W; label = free;}
border b4(t = 0.5
W, -0.5W){x = -0.5L; y = t ; label = fixed;}
border b5(t = -0.5L, 0.5L){x = t; y = -0.5W; label = free;}
border b6(t = -0.5
W, -0.025W){x = 0.5L; y = t; label = free; }
// Mesh
mesh th = buildmesh(b1(2s) + b2(24s) + b3
(200s) + b4 (50s) + b5 (200s) + b6 (24s));

// Fespace
fespace Vh(th, [P1, P1]);
Vh [ux, uy], [vx, vy], [uxd, uyd], [uxa, uya],
[vxa, vya], [uxn, uyn];
fespace Vh1 (th, P1);
Vh1 E, theta, thetaold, thetanew, dtheta, sens, sensn, sensv;
// Make intial design
theta = v;

I want to manually assign some initial design. I need some help to do that.
I manually defined coordinates in a text file and as:


mesh Thxy = triangulate(“coord.txt”);

I want to ask the following questions:
(i) How to manually assign some boundary nodes as “loaded” and “fixed” as in the case-1.
(ii) How to assign values of theta at some specific nodes/elements to be some specific value.