Several rectangles, fast way?

I'm trying to plot several rectangles (for an ultrasonic transducer simulation).

I tried to plot them with only one instruction but it doesn't works.

elementX = Matrix with Nx2 elements (normally N = 32). First column element start and second column element stop. Horizontal position.

elementY = Matrix (array) Nx1 elements. Vertical position of each element.

elementSize = Widh of each element.

0.005 = 5 milimeters of element high.

So, I tried it with repmat to create several arrays as a 'elegant' solution for avoiding a for loop. But it doesn't works :( Any help?

My NOT workin code:

 rectangle('Position',[elementX(:,1)*dh,elementY*dh,repmat(elementSize,N,1),repmat(0.005,N,1)],'FaceColor','y')

Thanks for your help :)

Answer 1

[Walter Roberson]

rectangle() will only plot a single rectangle per call.

plot() will produce one lineseries per column of input.

For example, the x coordinates can be constructed similar to

elementx(:,[1 2 2 1 1]).'

I do not understand about "5 millimeters of element high" ? Note for one thing that plotting units are normally data coordinates rather than millimeters.

[Walter Roberson]

Is elementSize perhaps the *height* of each element? So element K has Y coordinates elementY(K) to elementY(K)+elementSize(K) ? If not then I do not know how to deduce the height of the rectangle.

T = [elementY, elementY+elementSize];

plot( elementx(:,[1 2 2 1 1]), T(:,[1 1 2 2 1]) )

Answer 2

[Daniel]

Hi Walter,

thanks for your answer :)

This a plot for a FDTD programm where I simulate wave propagation through a liquid. When I said 5 mm I meant the x-y axis: element*dx. It is only for visualization, not for grid calculus.