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<DIV><SPAN class=256360218-18122000><FONT face=Arial color=#0000ff
size=2>Another hint: you don't actually have to make an instance of
vtkMath to use it for most (all?) of the methods because they are static
methods. So you can generally just do things like answer =
vtkMath::InvertMatrix(pt, pt2, 3) after making sure that pt is
invertible.</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
vtkusers-admin@public.kitware.com
[mailto:vtkusers-admin@public.kitware.com]<B>On Behalf Of </B>Harris Scott R
CIV AFRL/SNJM<BR><B>Sent:</B> Monday, 18 December 2000 12:01 PM<BR><B>To:</B>
'kalkie'; vtkusers@public.kitware.com<BR><B>Subject:</B> RE: [vtkusers]
vtkmath<BR><BR></FONT></DIV>
<DIV><SPAN class=240245916-18122000><FONT face=Arial color=#0000ff size=2>I'm
not familiar with vtkMath, but both of the matrices in your code have a zero
determinant; They don't have an inverse.</FONT></SPAN></DIV>
<DIV><SPAN class=240245916-18122000><FONT face=Arial color=#0000ff
size=2>-Scott Harris</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> kalkie
[mailto:jkalkman@HOTMAIL.COM]<BR><B>Sent:</B> Monday, December 18, 2000 9:19
AM<BR><B>To:</B> vtkusers@public.kitware.com<BR><B>Subject:</B> [vtkusers]
vtkmath<BR><BR></FONT></DIV>
<DIV><FONT face=Garamond size=4>Dear VTK-users,</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><FONT face=Garamond size=4>i'm quite new to vtk. Can anybody help me
with the vtkMath method? I want to invert a matrix. In the code as shown
below the variable 'answer' has the value zero, so the inverse is not
calculated. Probably the M-Time has to be updated, but I don't know how
to do that on an object of the vtkMath class.</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><FONT face=Garamond size=4>Thanks in advance,</FONT></DIV>
<DIV><FONT face=Garamond size=4>Jeroen Kalkman</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><FONT face=Garamond size=4>double **pt, **pt2;<BR>vtkMath* M =
vtkMath::New();</FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2></FONT> </DIV>
<DIV><FONT face=Garamond size=4>void main()<BR>{<BR> pt = new double*
[3], pt2 = new double* [3]; <BR> for(int q=0; q<3; q++) pt[q] = new
double [3], pt2[q] = new double [3];<BR> pt[0][0]=pt[0][1] = pt[0][2] =
1;<BR> pt[1][0]=pt[1][1] = pt[1][2] = 2;<BR> pt[2][0]=pt[2][1] =
pt[2][2] = 3;<BR> pt2[0][0]=pt2[0][1] = pt2[0][2] =
0;<BR> pt2[1][0]=pt2[1][1] = pt2[1][2] =
0;<BR> pt2[2][0]=pt2[2][1] = pt2[2][2] = 0;<BR> answer =
M->InvertMatrix(pt,pt2,3);<BR>}</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>