lets say i have arrays:
a = array((1,2,3,4,5))
indices = array((1,1,1,1))
and i perform operation:
a[indices] += 1
the result is
array([1, 3, 3, 4, 5])
in other words, the duplicates in indices are ignored
if I wanted the duplicates not to be ignored, resulting in:
array([1, 6, 3, 4, 5])
how would I go about this?
the example above is somewhat trivial, what follows is exactly what I
am trying to do:
def inflate(self,pressure):
faceforces = pressure *
cross(self.verts[self.faces[:,1]]-self.verts[self.faces[:,0]],
self.verts[self.faces[:,2]]-self.verts[self.faces[:,0]])
self.verts[self.faces[:,0]] += faceforces
self.verts[self.faces[:,1]] += faceforces
self.verts[self.faces[:,2]] += faceforces
def constrain_lengths(self):
vectors = self.verts[self.constraints[:,1]] -
self.verts[self.constraints[:,0]]
lengths = sqrt(sum(square(vectors), axis=1))
correction = 0.5 * (vectors.T * (1 - (self.restlengths / lengths))).T
self.verts[self.constraints[:,0]] += correction
self.verts[self.constraints[:,1]] -= correction
def compute_normals(self):
facenormals =
cross(self.verts[self.faces[:,1]]-self.verts[self.faces[:,0]],
self.verts[self.faces[:,2]]-self.verts[self.faces[:,0]])
self.normals.fill(0)
self.normals[self.faces[:,0]] += facenormals
self.normals[self.faces[:,1]] += facenormals
self.normals[self.faces[:,2]] += facenormals
lengths = sqrt(sum(square(self.normals), axis=1))
self.normals = (self.normals.T / lengths).T
Ive been getting some very buggy results as a result of duplicates
being ignored in my indexed inplace add/sub operations.