Re: [eigen] signal invalid matrix or vector

[Christoph Hertzberg <chtz@xxxxxxxxxxxxxxxxxxxxxxxx>]

On 2016-01-26 17:27, Christian Keck wrote:
> Is it possible to set the size of a matrix oder vector to zero? How can
> the elements of a vector set to a NaN? My compiler (Microsoft Visual C++
> 2013) does not yet support assignments with signalling NaNs.

You can resize matrices/vectors to 0 using the resize method:
  vector.resize(0);
  matrix.resize(0,0);
However, this does not work for fixed-sized matrices/vectors, i.e., 
Matrix2d, Vector3f, etc.
You can also set a matrix/vector to NaN, e.g. by:
  matrix.setConstant(0.0/0.0);
and check using
  bool invalid = matrix.hasNaN();

Christoph




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