geometryimages.m File Reference

Functions
function	geometryimages (nm, typ) bury_output()
	if (strcmp(typ,"png")) set(0
*endif	if (isempty(findstr(octave_config_info("DEFS"),"HAVE_QHULL"))&&(strcmp(nm,"voronoi")||strcmp(nm,"griddata")||strcmp(nm,"convhull")||strcmp(nm,"delaunay")||strcmp(nm,"triplot"))) sombreroimage(nm
	elseif (strcmp(typ,"txt")) image_as_txt(nm)
	elseif (strcmp(nm,"voronoi")) rand("state"
	triplot (tri, x, y,"b") = voronoi (x, y, tri)
	plot (vx, vy,"r")
	plot (xc, yc,"g-","LineWidth", 3)
	axis ([0, 1, 0, 1])
	legend ("Delaunay Triangulation","Voronoi Diagram")
	print (cstrcat(nm,".", typ), cstrcat("-d", typ)) elseif(strcmp(nm
triplot	rand ("state", 2) x = rand (20, 1)
	triplot (tri, x, y)
griddata	rand ("state", 1)
	griddata (x, y, z, xx, yy) = meshgrid(linspace(-1,1,32))
	plot (x(k), y(k),'r-', x, y,'b+')
	x (T(:, 2))
	x (T(:, 3))
	x (T(:, 1))]
	y (T(:, 2))
	y (T(:, 3))
	y (T(:, 1))]
	plot (X, Y,"b", x, y,"r*")
inpolygon	randn ("state", 2)
	plot (vx, vy, x(in), y(in),"r+", x(!in), y(!in),"bo")
endif	bury_output () = figure (1)
	set (f,"visible","off")
	if (strcmp(nm,"voronoi")) rand("state"
endfunction function	sombreroimage (nm, typ) if(strcmp(typ
	fputs (fid,"+-----------------------------+\n")
	fputs (fid,"| Image unavailable because |\n")
	fputs (fid,"| of a missing QHULL library. |\n")
	fclose (fid)
	title ("Sorry, graphics not available because octave was\\ncompiled without the QHULL library.")
end_unwind_protect endif endfunction function	image_as_txt (nm) fid
	fputs (fid,"\n")
	fputs (fid,"+---------------------------------+\n")
	fputs (fid,"| Image unavailable in text mode. |\n")
Variables
	defaulttextfontname
*endif	typ = -1
	x = rand(10,1)
	y = rand(10,1)
	tri = delaunay (x, y)
hold	on = meshgrid(x,y)
	pc = tri2circ (tri(end,:), x, y) [-1:0.01:1]
	xc = r * sin(pi*pc) + c(1)
	yc = r * cos(pi*pc) + c(2)
	z = sin(2*(x.^2+y.^2))
	k = convhull (x, y)
	T = delaunay (x, y)
	X = [ x(T(:,1))
	Y = [ y(T(:,1))
	vx = cos (pi * [-1 : 0.1: 1])
	vy = sin (pi * [-1 : 0.1 : 1])
	in = inpolygon (x, y, vx, vy)
endfunction	function [r, c]
	m = (y(1:end-1) - y(2:end)) ./ (x(1:end-1) - x(2:end))
	c = [xc, yc]
	r = sqrt ((xc - x(1)).^2 + (yc - y(1)).^2)
endfunction function txt	fid = fopen (sprintf ("%s.txt", nm), "wt")
	return
unwind_protect	mesh (x, y, z)

---

Function Documentation

axis

(

)

bury_output

(

)

= figure (1)

elseif

(

strcmp(nm,"voronoi")

)

elseif

(

strcmp(typ,"txt")

)

fclose

(

fid

)

fputs	(	fid	,
		"| Image unavailable in text mode. |\n"
	)

fputs	(	fid	,
		"+---------------------------------+\n"
	)

fputs	(	fid	,
		"\n"
	)

fputs	(	fid	,
		"| of a missing QHULL library. |\n"
	)

fputs	(	fid	,
		"| Image unavailable because |\n"
	)

fputs	(	fid	,
		"+-----------------------------+\n"
	)

endfunction function geometryimages	(	nm	,
		typ
	)

griddata	(	x	,
		y	,
		z	,
		xx	,
		yy
	)			= meshgrid(linspace(-1,1,32))

if

(

strcmp(nm,"voronoi")

)

* endif if

(

isempty(findstr(octave_config_info("DEFS"),"HAVE_QHULL"))&&(strcmp(nm,"voronoi")||strcmp(nm,"griddata")||strcmp(nm,"convhull")||strcmp(nm,"delaunay")||strcmp(nm,"triplot"))

)

Type Constraints

if

(

strcmp(typ,"png")

)

end_unwind_protect endif endfunction function image_as_txt

(

nm

)

legend	(	"Delaunay Triangulation"	,
		"Voronoi Diagram"
	)

plot	(	vx	,
		vy	,
		x(in)	,
		y(in)	,
		"r+"	,
		x(!in)	,
		y(!in)	,
		"bo"
	)

plot	(	X	,
		Y	,
		"b"	,
		x	,
		y	,
		"r*"
	)

plot	(	x(k)	,
		y(k)	,
		'r-'	,
		x	,
		y	,
		'b+'
	)

plot	(	xc	,
		yc	,
		"g-"	,
		"LineWidth"	,
		3
	)

plot	(	vx	,
		vy	,
		"r"
	)

unwind_protect_cleanup print	(	cstrcat(nm,".", typ)	,
		cstrcat("-d", typ)
	)

griddata rand	(	"state"	,
		1
	)

errorbar rand	(	"state"	,
		2
	)			= rand (20, 1)

inpolygon randn	(	"state"	,
		2
	)

set	(	f	,
		"visible"	,
		"off"
	)

endif endfunction function sombreroimage	(	nm	,
		typ
	)

title	(	"	Sorry,
		graphics not available because octave was\\ncompiled without the QHULL library."
	)

triplot	(	tri	,
		x	,
		y
	)

triplot	(	tri	,
		x	,
		y	,
		"b"
	)			= voronoi (x, y, tri)

x

(

T(:, 1)

)

x

(

T(:, 3)

)

x

(

T(:, 2)

)

y

(

T(:, 1)

)

y

(

T(:, 3)

)

y

(

T(:, 2)

)

---

Variable Documentation

c = [xc, yc]

defaulttextfontname

endswitch fid = fopen (sprintf ("%s.txt", nm), "wt")

endfunction function

Initial value:

 tri2circ (tri, xx, yy)
  x = xx(tri)

in = inpolygon (x, y, vx, vy)

for k = convhull (x, y)

id m = (y(1:end-1) - y(2:end)) ./ (x(1:end-1) - x(2:end))

unwind_protect mesh(x, y, z)

hold on = meshgrid(x,y)

pc = tri2circ (tri(end,:), x, y) [-1:0.01:1]

r = sqrt ((xc - x(1)).^2 + (yc - y(1)).^2)

endif return

T = delaunay (x, y)

x tri = delaunay (x, y)

else typ = -1

vx = cos (pi * [-1 : 0.1: 1])

vy = sin (pi * [-1 : 0.1 : 1])

endif X = [ x(T(:,1))

catch x = rand(10,1)

xc = r * sin(pi*pc) + c(1)

endif Y = [ y(T(:,1))

otherwise y = rand(10,1)

yc = r * cos(pi*pc) + c(2)

z = sin(2*(x.^2+y.^2))