Tutorials Code return "UndefVarError: ForwardConstraintFunction not defined"

[dmayfrank]

Hello,
sorry, this is probably a pretty basic question, I'm very new to Julia.

I'm trying to run the tutorial-files but I always get an error when trying to set the sensitivities. For example in line 140 of matrix-inversion-manual.jl (https://github.com/jump-dev/DiffOpt.jl/blob/master/docs/src/examples/matrix-inversion-manual.jl).

The full error message is:
_UndefVarError: ForwardConstraintFunction not defined

Stacktrace:
[1] getproperty(x::Module, f::Symbol)
@ Base ./Base.jl:35
[2] top-level scope
@ In[1]:140
[3] eval
@ ./boot.jl:373 [inlined]
[4] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
@ Base ./loading.jl:1196_

I tried adding these two lines of code which I found in another example, but this also did not help:

import MathOptInterface
const MOI = MathOptInterface

Apart from that I'm also struggling to understand the meaning of the syntax in the code used to set the sensitivities:

# set sentivitity
MOI.set(
    model,
    DiffOpt.ForwardConstraintFunction(),
    cons[1],
    0.0 * index(x[1]) - 1.0,  # to indicate the direction vector to get directional derivatives
)

and in the code used to query the derivatives:

# Query derivative
dx = MOI.get.(
    model,
    DiffOpt.ForwardVariablePrimal(),
    x,
)

Is there some documentation on these functions somewhere?

Thanks a lot for your help!

[matbesancon]

hi, thanks for reaching out, this is because of a breaking change which happened in recent PRs #210 #214 #216
To have it working, you need to add the master branch of DiffOpt instead of the stable version, we will release a new version soon

See here here to add a package on a given branch

[dmayfrank]

Thanks for the quick response, it works now!

I will try to understand the exact meaning of the syntax in the code mentioned above tomorrow.