[mlpack] How to do linear regression?

[Ryan Curtin]

On Tue, Jun 12, 2018 at 11:46:09PM +0800, Jason Liu wrote:
> Hi,
> 
> I copy-pasted some code from mlpack doc
> 
> ...
> 
> Unfortunately it gives me
> 
> 
> error: Mat::init(): requested size is not compatible with row vector layout
> 
> The exception was thrown at the LinearRegression ctor.
> 
> What does the error message mean?
> 
> What did I do wrong?

Ah!  I think the tutorial was not updated when the LinearRegression API
changed.  Try changing the line

  arma::vec responses;

to

  arma::rowvec responses;

And then it will need to be filled differently:

  responses << 1.0 << 2.0 << 3.0 << 4.0 << 5.0;

(Instead of the several lines that each end with arma::endr.)

If that fixes your problem, I'll update the tutorials.  Sorry for the
error!

-- 
Ryan Curtin    | "You got to stick with your principles."
ryan at ratml.org |   - Harry Waters