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[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

> 1) //! stretch ratio ?(n) 
> (http://en.wikipedia.org/wiki/Finite_strain_theory#Stretch_ratio)
>
> This comment is wrong, the strectch ratio is |F.x|/|x|, which is a 
> function of non-diagonal terms. The values returned by getStretchRatio 
> are not stretchRatios, they have no clear meaning and are not 
> invariants of F.
> As mentionned before, out of diagonal terms have an effect on stretch 
> ratios (this is why I don't know how to work with _size without Hsize).
One more comment to avoid future misunderstandings : the stretch ratio 
is not the strain. For instance a stretch of 0.5 (size divided by 2) 
corresponds to a strain log(0.5)=-0.69.

Bruno



>


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