MethodError: no method matching length(::Variable)

[quantumhub]

Thanks for this great work which makes FG inference a lot easier!
In demo (ForneyLab.jl-master/demo/bayes_rule_2d.ipynb)
Slightly change of the calculation in factor graph makes it fail:

@rv y ~ GaussianMeanVariance(A*(x.^2) + b, Sigma_y) # Likelihood

The error message is:
MethodError: no method matching length(::Variable)

Could any one help? Thanks.

[albertpod]

Hi @quantumhub! Thanks for trying out ForneyLab.

Unfortunately, Variable type doesn't support broadcasting.
If you want to apply a quadratic function to a multivariate Gaussian random variable you can (1) use a Nonlinear node (see demo/variational_laplace_and_sampling.ipynb), (2) define your own node or Composite node and provide the required update rules for it (see demo/composite_nodes.ipynb).

It will be useful if you provide the entire snippet where you specify your model.

[quantumhub]

Thank you for this answer! The nonlinear function in demo/variational_laplace_and_sampling.ipynb is very helpful for my application!