Creating of Basic Shape in Matlab

Hello!

I am trying to create a rectangle as a basic shape. I use these commands:

rect=[3 4 -1 1 1 -1 -0.5 -0.5]; 
gd=[rect];
ns=char('rect');
sf='rect';
dl = decsg(gd,sf,ns)

But in the end I get the following error message:

Index exceeds matrix dimensions.

What is wrong with my script? I do not fully understand what the following sentences means: "3 through 6 - x-coordinate of edge starting points" and "7 through 10 - y-coordinate of edge starting points"(from MATLAB help desk). Would somebody explain me this?

I want to get a solid geometry. 'decsg' means Decompose Constructive Solid Geometry into minimal regions. I follow this example http://se.mathworks.com/help/pde/ug/create-geometry-at-the-command-line.html but cannot get a shape.

Sergey

Answer 1

[Star Strider]

I don’t have much recent experience with the PDE Toolbox, but your ‘rect’ assignment is missing the last two y-coordinates for your rectangle:

rect=[3 4 -1 1 1 -1 -0.5 -0.5 # #];

where the ‘#’ indicate the missing coordinates.

In the documentation for Create CSG Geometry at the Command Line, the ‘3 through 6’ and ‘7 through 10’ refers to the vector needing four x (in elements 3-6) and four y (in elements 7-10) coordinates to define the rectangle’s corners.

EDIT — The error, ‘Index exceeds matrix dimensions.’ means that the relevant PDE routine is looking for the last two elements in your ‘rect’ vector and can’t find them.

[Sergey Dukman]

Hello!

Thank you, Sir.

now it is understandable. I will try all over again.

Sergey

[Star Strider]

My pleasure!