lol, <wipes tear from eye> that's just funny.
On 11/10/05, Shi Mu <[EMAIL PROTECTED]> wrote: > the Internet is down for one day and so wonderful to have so many > responses. i have checked all the links you guys mentioned. what i > want is delaunay triangulation and the available ones online are > written in C, Java and FORTRAN. I want to see some in Python because > it is hard for me to figure out using python to do Fortune's sweeping > line algorithm. Is python is not good in doing that kind of > computation or some other reason? > Thanks a lot for all of your responses!!! > > On 11/9/05, Gregor Lingl <[EMAIL PROTECTED]> wrote: > > > > > > Alex Hunsley schrieb: > > > Shi Mu wrote: > > > > > > > > >>is there any sample code of triangulation? many thanks! > > >> > > >> > > > > > > Yes, probably. > > > > > > > > > Indeed, there is. > > See attachment > > > > regards > > Gregor > > > > > > > > _______________________________________________ > > > Tutor maillist - Tutor@python.org > > > http://mail.python.org/mailman/listinfo/tutor > > > > > > > > > > -- > > Gregor Lingl > > Reisnerstrasse 3/19 > > A-1030 Wien > > > > Telefon: +43 1 713 33 98 > > Mobil: +43 664 140 35 27 > > > > Website: python4kids.net > > > > > > ## Run this program and create a polygon without > > ## intersecting edges by clicking the vertices with the mouse > > > > from Tkinter import * > > > > def area2(A,B,C): > > """2 * Flaeche des 2D-Dreiecks ABC""" > > return (A[0]-C[0])*(B[1]-C[1]) - (A[1]-C[1])*(B[0]-C[0]) > > > > def insideTriangle(A, B, C, P): > > """Liegt P im Dreieck ABC?, > > ABC sind im Gegenuhrzeigersinn angenommen!""" > > return area2(A,B,P)>=0 and area2(B,C,P)>=0 and area2(C,A,P)>=0 > > > > def triangulate(poly): > > tri = [] > > while len(poly) > 2: > > triaFound = False > > count = 0 > > while not triaFound and count < len(poly): #n: > > count += 1 > > A, B, C = poly[:3] > > if area2(A, B, C) >= 0: > > for P in poly[3:]: > > if insideTriangle(A,B,C,P): > > break > > else: > > tri.append( (A,B,C) ) > > poly.remove(B) > > triaFound = True > > poly.append(poly.pop(0)) > > if count == len(poly): # n: > > print "Not a simple polygon" > > return None > > return tri > > > > > > class CvDefPoly(Canvas): > > def __init__(self, root): > > Canvas.__init__(self, root, bg="white", cursor="crosshair") > > self.v = () > > self.rWidth, self.rHeight = 10.0, 7.5 > > > > self.bind("<Configure>", self.repaint) > > self.bind("<Button-1>", self.mousePressed) > > > > self.done = False > > > > def mousePressed(self, event): > > if self.done: > > self.done = False > > self.v = () > > x ,y = self.fx(event.x), self.fy(event.y) > > if self.v: > > x0, y0 = self.v[:2] > > if abs(x-x0)<self.rWidth*0.01 and > abs(y-y0)<self.rHeight*0.01: > > self.done = True > > if not self.done: > > self.v += (x,y) > > self.repaint(None) > > > > def iX(self,x): > > return self.centerX + x/self.pixelSize > > def iY(self,y): > > return self.centerY - y/self.pixelSize > > def fx(self,x): > > return (x-self.centerX)*self.pixelSize > > def fy(self,y): > > return (self.centerY - y)*self.pixelSize > > > > def repaint(self, event): > > items = self.find_all() > > for item in items: > > self.delete(item) > > if event: > > self.w, self.h = event.width, event.height > > w,h = self.w, self.h > > self.minX = self.minY = 2.0 > > self.maxX, self.maxY = w-3.0, h-3.0 > > dx, dy = self.maxX-self.minX, self.maxY-self.minY > > self.centerX = 2.0 + dx/2.0 > > self.centerY = 2.0 + dy/2.0 > > self.pixelSize = max(self.rWidth/dx, self.rHeight/dy) > > > > left = self.iX(-self.rWidth/2.0) > > right = self.iX(self.rWidth/2.0) > > bottom = self.iY(-self.rHeight/2.0) > > top = self.iY(self.rHeight/2.0) > > > > self.create_rectangle(left,top,right,bottom, outline="red") > > if len(self.v) > 1: > > x,y = self.v[:2] > > self.create_rectangle(self.iX(x)-2, self.iY(y)-2, > > self.iX(x)+2, self.iY(y)+2, > outline="green") > > if len(self.v) > 3: > > if self.done: > > v = [] > > sv = self.v[:] > > while sv: > > a,b=sv[:2] > > v.extend([self.iX(a), self.iY(b)]) > > sv = sv[2:] > > self.create_polygon( v, fill="", outline="blue") > > else: > > coo = list(self.v[2:]) > > while coo: > > x1,y1 = coo[:2] > > self.create_line(self.iX(x),self.iY(y), > > self.iX(x1),self.iY(y1),fill="blue") > > x,y=x1,y1 > > coo = coo[2:] > > > > def ccw(poly): > > n = len(poly) > > k = poly.index(min(poly)) > > return area2(poly[k-1], poly[k], poly[(k+1)%n]) > 0 > > > > def color(n): > > return "#%02x%02x%02x" % (255-n,0,n) > > > > class PolyTria(Tk): > > def __init__(self): > > Tk.__init__(self) > > self.geometry("500x300-10+50") > > self.title("Define polygon vertices by clicking") > > CvPolyTria(self).pack(expand=1, fill="both") > > > > class CvPolyTria(CvDefPoly): > > def repaint(self, event): > > doit = False > > if len(self.v)>3 and self.done: > > poly = [] > > v = self.v[:] > > while v: > > p = tuple(v[:2]) > > poly.append(p) > > v = v[2:] > > if not ccw(poly): > > poly.reverse() > > tri = triangulate(poly) > > doit = True > > CvDefPoly.repaint(self, event) > > if doit: > > anz = len(tri) > > diff = 255//anz > > for i,t in enumerate(tri): > > (x1,y1),(x2,y2),(x3,y3) = t > > t = > (self.iX(x1),self.iY(y1),self.iX(x2),self.iY(y2),self.iX(x3),self.iY(y3)) > > self.create_polygon(t, fill=color(i*diff), > outline="black") > > > > if __name__ == "__main__": > > PolyTria().mainloop() > > > > > > > _______________________________________________ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
