How to Make Transparent Rectangles

[omegayen]

I tried looking for solutions to this but am still at loss.

How do I make a rectangle semi-transparent?

I can draw a rectangle with

rectangle('Position',[0 3 1 1],'EdgeColor','blue','FaceColor',[0 0 0])

but rectangle does not have a FaceAlpha property

I see something about using annotation

but get an error when position values are outside of 1

annotation('rectangle',[0 3 1 1])
??? Error using ==> annotation at 130
position values must be between 0 and 1

so does anyone know how I can draw a semi transparent rectangle? thanks.

[Sean de]

"omegayen " <omeg...@ameritech.net> wrote in message <ieg9od$8nc$1...@fred.mathworks.com>...

ANNOTATION uses a percentage of the figure size instead of coordinates.

For example:
figure;
annotation('rectangle',[.2 .4 .1 .1]);
% 20% across x, 40% across y, 10% width,10%height

-Sean

[Walter Roberson]

On 10-12-17 12:22 PM, omegayen wrote:
> I tried looking for solutions to this but am still at loss.
>
> How do I make a rectangle semi-transparent?

You can't. Use a patch() instead. (In general, this may require calculating
the vertices of the approximation to the curve, if you specify curvature. The
example you gave is a straight-forward four-vertex patch.)