Plot red lines on a contourf plot

Hi everybody, I am trying to create rectangles to identify some areas within a contourf plot. For the moment being, I thought of creating lines between points in the space.

I am not getting the result wanted, I only get 2 lines which I assume are represented because they are just on the rims of the contourf plot. How do I get all of them to be represented in the plot?

I attach the code hereby:

 x1=[0.4:2.5:97.9,99.9];
y2=[7.9:-1.5:0.4];
y1=y2';
[X1,Y1] = meshgrid (x1,y1);
%-------
HV_NDTD1=[466, 468, 440, 463, 463, 480, 444, 463, 454, 446, 468, 448, 463, 461, 457, 452, 477, 440, 448, 463, 466, 480, 477, 459, 457, 455, 444, 448, 461, 442, 452, 435, 448, 444, 470, 463, 461, 457, 463, 459, 450;
         452, 487, 475, 470, 457, 487, 468, 475, 497, 461, 475, 463, 494, 435, 472, 487, 444, 468, 472, 450, 470, 450, 470, 461, 461, 448, 463, 457, 463, 480, 457, 457, 463, 468, 466, 492, 459, 472, 455, 475, 472;
         418, 442, 429, 412, 404, 410, 403, 423, 427, 418, 427, 438, 461, 446, 442, 448, 435, 440, 437, 431, 448, 431, 433, 455, 431, 472, 435, 444, 470, 446, 484, 442, 448, 450, 477, 446, 468, 459, 477, 452, 470;
         408, 394, 394, 399, 418, 416, 392, 403, 423, 425, 406, 414, 406, 435, 425, 435, 431, 446, 427, 454, 406, 448, 429, 438, 448, 454, 446, 444, 450, 446, 466, 440, 420, 461, 425, 448, 466, 459, 452, 468, 461;
         423, 423, 442, 431, 404, 412, 418, 406, 397, 446, 454, 448, 433, 442, 466, 461, 461, 450, 440, 440, 440, 452, 457, 452, 440, 448, 468, 475, 440, 461, 448, 463, 466, 444, 455, 475, 440, 452, 442, 433, 463;
         410, 403, 480, 468, 440, 442, 446, 446, 452, 410, 431, 457, 468, 454, 450, 470, 431, 423, 470, 459, 454, 435, 455, 461, 457, 459, 468, 470, 468, 466, 468, 461, 461, 468, 477, 487, 457, 468, 475, 463, 452;];
%------
xLINE1=[35.3 99.9];
yLINE1=[0.4 0.4];
xLINE2=[35.3 99.9];
yLINE2=[3.3 3.3];
xLINE3=[40.3 99.9];
yLINE3=[5 5];
xLINE4=[40.3 99.9];
yLINE4=[7.9 7.9];
xLINE5=[35.3 35.3];
yLINE5=[0.4 3.3];
xLINE6=[40.3 40.3];
yLINE6=[0.4 3.3];
%---------
figure(3);
plot(xLINE1,yLINE1,'r-','linewidth',6)
hold on;
plot(xLINE2,yLINE2,'r-','linewidth',6)
plot(xLINE3,yLINE3,'r-','linewidth',6)
plot(xLINE4,yLINE4,'r-','linewidth',6)
plot(xLINE5,yLINE5,'r-','linewidth',6)
plot(xLINE6,yLINE6,'r-','linewidth',6)
contourf(X1,Y1,HV_NDTD1)
colormap(parula(32))
colorbar
hold off;
xlabel('Distance (mm)','FontSize',16)
ylabel('Distance (mm)','FontSize',16)
title('W80 Plate ND/TD Bar Hardness Map (facing encapsulated samples)','FontSize',22,'FontWeight','bold')
set(gca,'fontsize',24,'fontweight','bold','linewidth',3);
x1 = [.8,.775];
y1 = [0.965,0.935];
a = annotation('textarrow',x1,y1,'String','Front RD/TD-surface','fontweight','bold');
a.Color = 'red';
a.FontSize = 20;
x1 = [.1,.125];
y1 = [0.85,0.775];
a = annotation('textarrow',x1,y1,'String','Crizzled side','fontweight','bold');
a.Color = 'red';
a.FontSize = 20;

Answer 1

[Geoff Hayes]

uCiucani - try drawing the red lines after you have created the contour plot as

contourf(X1,Y1,HV_NDTD1)
hold on;
plot(xLINE1,yLINE1,'r-','linewidth',6)
plot(xLINE2,yLINE2,'r-','linewidth',6)
plot(xLINE3,yLINE3,'r-','linewidth',6)
plot(xLINE4,yLINE4,'r-','linewidth',6)
plot(xLINE5,yLINE5,'r-','linewidth',6)
plot(xLINE6,yLINE6,'r-','linewidth',6)

Or, better, is to use uistack to re-order the visual stacking order of the graphics objects. In this case, you would "put" the contour plot at the bottom of the stack

figure(3);
hold on;
plot(xLINE1,yLINE1,'r-','linewidth',6)
plot(xLINE2,yLINE2,'r-','linewidth',6)
plot(xLINE3,yLINE3,'r-','linewidth',6)
plot(xLINE4,yLINE4,'r-','linewidth',6)
plot(xLINE5,yLINE5,'r-','linewidth',6)
plot(xLINE6,yLINE6,'r-','linewidth',6)
[~, hCP] = contourf(X1,Y1,HV_NDTD1);
uistack(hCP,'bottom');

Try the above and see what happens!

[uCiucani]

It worked, thank you very much Geoff!!