What seems to be the problem with this rotation here (python-code) ?

I’m drawing an arrow from (x1,y1,z2) to (x2,y2,z2). Please see this and I hope you can explain what is going on…

```
def coordSysArrow(x1, y1, z1, x2, y2, z2):
glPushMatrix()
glPushAttrib( GL_POLYGON_BIT ) # includes GL_CULL_FACE
glDisable(GL_CULL_FACE) # draw from all sides
# Size of cone in arrow:
coneFractionAxially = 0.2
coneFractionRadially = 0.1
# Calculate cone parameters:
v = numpy.array((x2-x1, y2-y1, z2-z1))
norm_of_v = numpy.sqrt( numpy.dot(v,v) )
coneHgt = coneFractionAxially * norm_of_v
coneRadius = coneFractionRadially * norm_of_v
vConeLocation = (1.0-coneFractionAxially) * v
# Construct transformation matrix
mat44 = numpy.eye(4)
normalized_v = v/norm_of_v
mat44[0,0] = normalized_v[0]
mat44[1,1] = normalized_v[1]
mat44[2,2] = normalized_v[2]
# -----------------------
# Draw line + cone
# -----------------------
# Draw single line:
glBegin(GL_LINES)
glVertex3f(x1, y1, z1) # from
glVertex3f(x2, y2, z2) # to
glEnd() # GL_LINES
# Move and rotate in position:
glTranslate( *vConeLocation )
if 0: # turn on/off here
#glLoadIdentity()
glMultMatrixf( mat44 ) # <===== PROBLEM HERE?!?! WHAT?
# Make a cone!
cone_obj = gluNewQuadric();
# gluCylinder(gluNewQuadr, Radius_base, Radius_top,
# height, slices, stacks)
gluCylinder(cone_obj, 0, coneRadius,\
coneHgt, 8, 1);
glPopAttrib() # GL_CULL_FACE
glPopMatrix()
```

As you can see I’ve made an option to disable using the mat44-matrix. When I disable it, the cone gets drawn but the rotation is wrong. When I enable it, the cone is NOT drawn… Am I multiplying with a wrong rotation matrix and does that explain why nothing gets drawn?

There are no errors/warnings or anything… I don’t understand this…