# [Maya-Python] Matrix inverse of several transformations ?

```I'm relatively new in the matrix game , I'm trying to apply some rotation ,
position and scale in one matrix on a object,
and it did work , I just had to multiply the matrices together to obtain
one transformation matrix, it does its job but the problem is that I need at
some point to revert the changes, like all of them , and when I'm trying to
inverse the "master matrix" I open a black hole and the object is no longer
how it was before```
```
:

```python
# matrix to position to center
pos_mat = om.MMatrix( [
(1,0,0,0),
(0,1,0,0),
(0,0,1,0),
(-o.x,-o.y,-o.z,1) ] )

# matrix to flatten on y
scale_mat = om.MMatrix( [
(1,0,0,0),
(0,0,0,0),
(0,0,1,0),
(0,0,0,1)] )

fnmat = ( pos_mat * rot_mat ) * scale_mat
# fnmat = pos_mat

for i in xrange( fnm.numVertices ):
fnm.setPoint( i , fnm.getPoint( i) * fnmat )
# fnm.getPoint( i) * fnmat.inverse() to reverse does not work / is
odd looking
```

so the question is how to reverse several transformations with one 'reverse
matrix' if it's possible

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