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我有一个 python 脚本，我从两个单独的文本文件中导入三角形元素的坐标和元素定义。我首先为每个三角形元素定义唯一节点，然后在三角形元素之间定义一个新的矩形元素（此 python 脚本为 FEM 计算编写输入文件）。

坐标文件如下所示：

id,x,y,
  1,  0,   0
  2,  0,   1
  3,  0,   2
  4,  1,   0
  5,  1,   1
  6,  1,   2
  7,  2,   0
  8,  2,   1
  9,  2,   2

元素文件如下所示：

id, n1, n2, n3
 1, 1, 2, 4
 2, 1, 2, 5
 3, 2, 3, 5
 4, 3, 5, 6
 5, 5, 6, 8
 6, 6, 8, 9
 7, 5, 7, 8
 8, 4, 5, 7

我想要发生的是三角形元素的节点的坐标被移动到三角形元素的质心，这样三角形元素之间的矩形元素将获得一个实际的厚度。

在此处输入图像描述

但是我在我的 python 脚本中做错了（见下文）。脚本中水平线之间的部分应该改变坐标。但是对于我的脚本，添加了额外的坐标，而不是（对于此处的示例）9 个初始坐标。并且坐标也没有朝正确的方向移动。

为什么会发生这种情况，我该如何解决？

#!/usr/bin/env python

# Inlezen coordinaten
open("D://Documents//SkyDrive//afstuderen//99 EEM - Abaqus 6.11.2//scripting//_COORDINATEN.txt", "r")
import csv
import itertools

with open("_COORDINATEN.txt") as file:
    data = csv.reader(file)
    next(data)
    coords = []
    coords = ([[float(x) for x in line[1:]] for line in data])

#inlezen elementen
open("D://Documents//SkyDrive//afstuderen//99 EEM - Abaqus 6.11.2//scripting//_ELEMENTEN.txt", "r")
import csv
import itertools

with open("_ELEMENTEN.txt") as file:
    data2 = csv.reader(file)
    next(data2)
    elems = []
    elems = ([[int(x)-1 for x in line[1:]] for line in data2])


#Flip the original elements if required
for i,elem in enumerate(elems):
    ecoords = [coords[e] for e in elem]

    a = [x2-x1 for x1,x2 in zip(ecoords[0],ecoords[1])]
    b = [x2-x1 for x1,x2 in zip(ecoords[1],ecoords[2])]

    n = a[0]*b[1]-a[1]*b[0]

    if n < 0:
        elems[i] = [ elem[0], elem[2], elem[1] ]

#bewerking elementen
newcoords = []
newelems  = []
for elem in elems:
    ecoords = [coords[e] for e in elem]
    newelem = range( len(newcoords), len(newcoords)+len(ecoords) )

    newcoords += ecoords
    newelems.append( newelem )

cohelems = []
for e,elem in enumerate(elems):
  for edge in [[0,1],[1,2],[2,0]]:

    eedge = [elem[i] for i in edge]

    for e2,elem2 in enumerate(elems[e+1:]):

      e2 += e+1

      for edge2 in [[0,1],[1,2],[2,0]]:

        eedge2 = [elem2[i] for i in edge2]

        if all([i in eedge2 for i in eedge]):

          newedge  = [newelems[e][i] for i in edge ]
          newedge += [newelems[e2][i] for i in edge2]

          cohelems.append( newedge[-1::-1] )
#---------------------------------------------------------------------
def add_vectors(*points):
  new_x = 0.0
  new_y = 0.0
  for point in points:
    new_x += point[0]
    new_y += point[1]
  return [new_x, new_y]

def subtract_vectors(a, b):
  new_x = a[0] - b[0]
  new_y = a[1] - b[1]
  return [new_x, new_y]


def mul_by_scalar(vector, scalar):
  new_x = vector[0] * scalar
  new_y = vector[1] * scalar
  return [new_x, new_y]

new_triangles = []
for elem in elems:
    new_triangles += [coords[e] for e in elem]

print 'new_triangles =', new_triangles

CM = mul_by_scalar(add_vectors(*new_triangles), 1.0/3)

point_to_CM_vectors = []
for point in new_triangles:
  point_to_CM_vectors.append(subtract_vectors(CM, point))

new_triangle2 = []
#for e,elem in enumerate(elems):
for elem in elems:
    for point, motion in zip(new_triangles, point_to_CM_vectors):
      new_triangle2.append(add_vectors(point, mul_by_scalar(motion, 0.01)))
#      new_triangle2 += [add_vectors(point, mul_by_scalar(motion, 0.01))]

print 'new_triangle2 =', new_triangle2
#---------------------------------------------------------------------

提前感谢大家的帮助！

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