Validating input

[vchuravy]

I would like to put constraints on my inputs making them either co-dependent or at least validate them take the following Gadfly plot

@manipulate for μ in -5:5, σ in 0:5, min in -10:0, max in 0:10
    dist = Normal(μ, σ)
    plot(x -> pdf(dist,x), min, max) 
end 

I would like to validated an input like this.

@manipulate for μ in -5:5, σ = 10, min = -10 , max = 10 | max >= min |  σ >= 0
    dist = Normal(μ, σ)
    plot(x -> pdf(dist,x), min, max) 
end 

[shashi]

validation is possible with simple if statements although you are going to have to return a plot at the end of the block so that it doesn't get replaced by nothing. Co-dependent widgets seems like a great idea but will be hard to get right. Will try to do this in a 0.2.0 release.

[vchuravy]

The idea of letting @manipulate handle validation would be that we could raise a warning at the front end and in the case that the validation fails, keep the last output.

[shashi]

Alright, that seems doable. Will try this soon.