Herman Sletmoen

Mixing variables and parameters in the `defaults` of the simple `remake` example ```julia using Test using ModelingToolkit using ModelingToolkit: t_nounits as t, D_nounits as D using DifferentialEquations @testset "remake with...

Custom independent variable leads to underdetermined initialization system

1

This trivial example works as it should, where the independent parameter `t` is imported as `ModelingToolkit.t_nounits`: ```julia using ModelingToolkit using DifferentialEquations using ModelingToolkit: t_nounits as t, D_nounits as d @variables...

Cannot evaluate spline parameter directly in an ODESystem

11

I want to evaluate a spline and its derivative(s) through an `ODESystem`. This works beautifully: ```julia using Test using ModelingToolkit using ModelingToolkit: t_nounits as t, D_nounits as D using DifferentialEquations...

Cannot (re)make problems with defaults involving the independent parameter

2

Currently, it seems to me that `remake` cannot reinitialize a system using `defaults` that involve the independent parameter (often `t`). It would be nice if this worked: ```julia using ModelingToolkit...

For reasons I do not understand, the example ```julia using ModelingToolkit @parameters A1 A2 B1 B2 # it fails with this line uncommented #@parameters A1 A2=1-A1 B1=A1 B2=A2 # it...

Check that equations contain at least one variable

11

I suggest throwing this nicer error to close #2727 ## Checklist - [x] Appropriate tests were added - [x] Any code changes were done in a way that does not...

Transform systems robustly by remaking systems

3

This is an attempt to strengthen the robustness of system transformations (i.e. processes that turn one system into another). Internally, as pointed out in #1710 and #1752, there is inconsistency...

Remake does not respect initial conditions of unknowns determined by initialization equations

3

This example fails (but passes with the commented line uncommented): ```julia using Test using ModelingToolkit using ModelingToolkit: t_nounits as t, D_nounits as D using DifferentialEquations @variables x(t) @named sys =...

Solve does not solve initialization problem of remade problems

1

I want to solve an `ODESystem` for many values of a parameter `P`, where the initial value for an unknown `x` depends on `P` (here I write a nonlinear initialization...

Type ambiguity in isequal(Num, ForwardDiff.Dual)

2

I want to fix https://github.com/SciML/ModelingToolkit.jl/issues/2997, and this seems to be the root cause: ```julia using Symbolics, ForwardDiff, Test @variables x xfunc(xval) = isequal(x, xval) ? xval : xval @test ForwardDiff.derivative(xfunc,...