在python中连接顶点来生成三角形

Question

我有一个像这样的双循环:

for i in xrange(len(myVVV)):
    for j in xrange(len(myVVV[i])):
        if myVVV[i][j]!= -1:
              s=i,j
              print(myVVV[i][j])
              print(s)

给了这个:

1
(0, 1)
2
(0, 5)
3
(1, 0)
4
(1, 1)
5
(1, 2)
6
(1, 4)
7
(1, 5)
8
(1, 6)
9
(2, 0)
10
(2, 1)
11
(2, 3)
12
(2, 4)
13
(3, 2)
14
(3, 3)
15
(3, 6)
16
(3, 7)
17
(4, 6)
18
(4, 7)

我试图通过检查点来创建"三角形"，s代表网格上数字点的位置，基本上我将连接点1,3,4，使一个基于那里的位置的三角形。有什么想法吗?

我能读的东西?我正在创建一个facet文件，这就是为什么我需要使三角形与顶点等

Answer 1

你可以试着把坐标倒过来——从而证明两个点彼此是对角线。你也可以用这个来检查对角线上是否有一个点。然后，把它们组合起来，检查在那个位置是否有一个点——如果有，你就得到了一个三角形。如

(0, 1) // One dot
Invert it to check for surrounding dots
(1, 0) // Dot found (inverted 0, 1)
(1, 1) // Combination - check if dot exists there. if true - triangle!

只是一个建议，可能会阻止一些想法走上正确的道路:)我只是想到了这个，所以如果你找到一个洞，请轻松:p

Answer 2

您检查过matplotlib了吗?这里的答案是用于绘制多边形

Answer 3

这是我的代码，它可以工作，对于未来的情况，如果人们需要它的感觉自由，希望它可以帮助

MTri=0 #num of triangles 
numI=len(myVVV)#to check in range of i
numJ=len(myVVV[0])# to check in range of j
idsT=0 #for triangles
for i in xrange(len(myVVV)):
#print(myVVV[i])
for j in xrange(len(myVVV[i])):
    if myVVV[i][j] != -1:
        # line below check that if point has neighboring
        #points open to make a sqaure makeing it counter clockwise 
        #-> right, ^ up, <- left, v down (first case)
        if i-1 >= 0 and j+1 < numJ and myVVV[i][j+1] !=-1 and myVVV[i-1][j+1] !=-1 and myVVV[i-1][j] != -1:
            MTri= MTri +2#plus 2 since 2 traingles are made from a square
            A=myVVV[i][j]
            B=myVVV[i][j+1]
            C=myVVV[i-1][j]
            D=myVVV[i-1][j+1] 
            idsT=idsT+1
            #A,B,D create -> right ,^ up, back   _|
            #A,D,C create corner , <- left, back |/  
            print("create Triangle from points" + ' '+str(A)+' '+ str(B)+' '+ str(D))
            openwrite.write(str(idsT)+' '+str(A)+ ' '+str(B)+' '+str(D)+'n')
            idsT=idsT+1
            openwrite.write(str(idsT)+' '+str(A)+ ' '+str(D)+' '+str(C)+'n')
            print("create Triangle from points" + ' '+str(A)+' '+ str(D)+' '+ str(C))

        elif i-1 >= 0 and j+1 < numJ and myVVV[i][j+1] != -1 and myVVV[i-1][j+1] != -1:
            MTri= MTri+1#plus 1 
            A=myVVV[i][j]
            B=myVVV[i][j+1]# same index ,j shift -> one to the right
            C=myVVV[i-1][j+1] # index above, j shifted -> one to the right
            #A,B,C creates ->right,^ up, back  _|
            idsT=idsT+1
            openwrite.write(str(idsT)+' '+str(A)+ ' '+str(B)+' '+str(C)+'n')
            print("create Triangle from points" + ' '+str(A)+' '+ str(B)+' '+ str(C))
        elif i-1 >= 0 and j+1 < numJ and myVVV[i][j+1] != -1 and myVVV[i-1][j] != -1:
            MTri= MTri+1#plus 1 
            A=myVVV[i][j]
            B=myVVV[i][j+1] #same index ,j shift -> one to the right
            C=myVVV[i-1][j]  #index above, same j position 
            #A,B,C creates ->right,corner, back  |_
            idsT=idsT+1
            openwrite.write(str(idsT)+' '+str(A)+ ' '+str(B)+' '+str(C)+'n')
            print("create Triangle from points" + ' '+str(A)+' '+ str(B)+' '+ str(C))

        elif i-1 >= 0 and j+1 < numJ and myVVV[i-1][j+1] != -1 and myVVV[i-1][j] != -1:
            MTri= MTri+1#plus 1 
            A=myVVV[i][j]
            B=myVVV[i-1][j+1] # index above, j shifted -> one to the right
            C=myVVV[i-1][j]  #index above, same j position 
            #A,B,C creates corner right, left back  |/
            idsT=idsT+1
            openwrite.write(str(idsT)+' '+str(A)+ ' '+str(B)+' '+str(C)+'n')
            print("create Triangle from points" + ' '+str(A)+' '+ str(B)+' '+ str(C))