Draw a polygon in the current plot.
patch(points, param1, value1, param2, value2... )
points A matrix of two columns containing the coordinates of the vertices of the polygon to be drawn, in the form [x1, y1; x2, y2; x3 y3 ;...] .
{param1, value1, param2, ...} Parameter value pairs to specify various optional paramaters associated with the line.

The points are in the units of the current data that is being displayed.

The optional parameters are set by specifying the name of the parameter as a string followed by its value. The following paramter-value pairs may be specified.

>>function seprinski(n)
>%Draws the Seprinski triangle in red with maximum recursion depth of n.
>% The locations of the triangle vertices
>x = [-1, 1, 0]';
>y = [ 0, 0, sqrt(3)]';
>hold off
>>function triangle(x,y,n,nmax)
>	if(n>nmax);return;end
>	a=patch([x,y],'color','red')
>	static ind1=[1:3],ind2=[2 3 1]';
>	if(n==0)
>		axis([min(x)-.1, max(x)+.1, min(y)-.1,max(y)+.1])
>		axis('square')
>		hold on
>	end
>	x1=(x[ind1]+x[ind2])/2;
>	y1=(y[ind1]+y[ind2])/2;
>	triangle([x[1],x1[1],x1[3]]',[y[1],y1[1],y1[3]]',n+1,nmax)
>	triangle([x1[1],x[2],x1[2]]',[y1[1],y[2],y1[2]]',n+1,nmax)
>	triangle([x1[3],x1[2],x[3]]',[y1[3],y1[2],y[3]]',n+1,nmax)