Segfault in Derivative about modelingtoolkit.jl HOT 2 CLOSED

This seems like a combination of user and internal error. Hopefully the internal error is solved in #84.

To get the desired behavior (which I'm assuming is differentiating f(x,y,z) with respect to x?), you should be able to use the following:

@Deriv D'~x

expand_derivatives(D(f(x,y,z)))

Derivative doesn't taken into account the chain rule. (In fact, it acts more as a database of partial derivative rules.) Thus, we instead construct a Differential object with respect to x using @Deriv D'~x, apply it to the desired expression, and (symbolically) expand the derivatives.

from modelingtoolkit.jl.

Yes, the Differential should be used, and Derivative is a behind the scenes way that it's actually implemented in the IR. We need to better separate the internals vs externals of the documentation here.

from modelingtoolkit.jl.