Confusion with vtkMath::InvertMatrix

[David Gobbi]

On the topic of 'unexpected output,'  vtkMath::InvertMatrix()
returns the transposed inverse of the matrix.  The 'transpose'
part of the operation is not mentioned in the man pages.

 - David

On Wed, 28 Jul 1999, Ben Held wrote:

> Ok, my apologies.  However, this function is used in ComputeXRange() in
> vtkXYPlotActor to compute the X range when VTK_XYPLOT_ARC_LENGTH is set.
> Therefore a sqrt is needed in the line:
> 
>      lengths[dsNum] += vtkMath::Distance2BetweenPoints(x,xPrev);
>  
> Thanks,
> 
> Ben
> 
> At 10:36 AM 7/28/99 -0400, you wrote:
> >Ben,
> >That method computes the square of the distance between two points as 
> >stated in the man page.
> >http://vtk.scorec.rpi.edu/Nightly/Doc/manhtml/vtkMath.html#method13
> >
> >This is for efficiency, since many uses of this value work with the squared 
> >distance.
> >
> >Bill
> >
> >At 08:58 AM 7/28/99 -0500, Ben Held wrote:
> >>Hello,
> >>
> >>I have discovered a major bug in vtkMath::Distance2BetweenPoints.  The
> >>return value needs to be passed through sqrt.
> >>Please make note of this so it can be fixed in 3.0.
> >>
> >>Ben
> >>
> >>John
> >>Ben L. Held
> >>Simulation Technology & Applied Research, Inc.
> >>11520 N. Port Washington Rd.
> >>Suite 101 B
> >>Mequon, WI  53092
> >>Phone: (414) 240-0293
> >>FAX: (414) 240-0294
> >>e-mail: ben.held at staarinc.com
> >>
> >>
> >>
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> >
> >
> >
> John
> Ben L. Held
> Simulation Technology & Applied Research, Inc.
> 11520 N. Port Washington Rd.
> Suite 101 B
> Mequon, WI  53092
> Phone: (414) 240-0293
> FAX: (414) 240-0294
> e-mail: ben.held at staarinc.com
> 
> 
> 
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