removing part of a box plot

boxx = [3;7;7;3;3];
boxy = [3;3;7;7;3];
figure(1)
boxing = plot(boxx,boxy);
xlim([0 11]);
ylim([0 11]);

the code above plots a simple box

how do i remove part of the box such as removing everything above y=6?

to be clearer, to remove the top, y=6 to y=7 part of the line from the left and right lines

ie, removing the blue lines above the green line shown in the picture below

the simple method i know of is to make a new plot by slightly changing the values in the code such as below

boxx = [3;3;6;6];
boxy = [6;3;3;6];
boxing = plot(boxx,boxy);

but since i need it to be dynamic where sometimes i want it at y=5 or y=6.5 and will use the same concept with other shapes such as circulars, triangulars or 2d polygons

is there a different method or code i can use to remove the lines?

[Rik]

You can't remove part of a line object, so you will have to use a similar tactic for your other shapes as well.

[Adam Danz]

If the box edges are always parallel to the axes, it's as easy as,

boxy(boxy>6) = 6;

[Adrian Lee]

for this case it will always be parallel, but for some other cases which i will tackle in the future, mostly will not be parallel to axes or each other

[Adam Danz]

Then you need to rotate the vertices using a rotation matrix before applying the height cuttoff.

[Adrian Lee]

ah, i see

hmm,

i would need an equation for identifying the length needed before the rotation

then use the rotation matrix for plotting a new line... or i am mistaken?

[Adam Danz]

No, that's not quite right.

If the edges of your rectangle are not parallel to the axes you'll need to rotate the rectangle so that it is parallel, then apply the cutoff, and then counter-rotate it back to its original orientation.