Skip to content

Handle split in linearize_symbolic #3968

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Oct 16, 2025
Merged

Handle split in linearize_symbolic #3968

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
03dc733
Handle `split` in `linearize_symbolic`
baggepinnen Oct 16, 2025
8feaf4c
Add tests for symbolic linearization functionality
baggepinnen Oct 16, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
15 changes: 10 additions & 5 deletions src/linearization.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -501,9 +501,9 @@ where `x` are differential unknown variables, `z` algebraic variables, `u` input
"""
function linearize_symbolic(sys::AbstractSystem, inputs,
outputs; simplify = false, allow_input_derivatives = false,
eval_expression = false, eval_module = @__MODULE__,
eval_expression = false, eval_module = @__MODULE__, split = true,
kwargs...)
sys = mtkcompile(sys; inputs, outputs, simplify, kwargs...)
sys = mtkcompile(sys; inputs, outputs, simplify, split, kwargs...)
diff_idxs, alge_idxs = eq_idxs(sys)
sts = unknowns(sys)
t = get_iv(sys)
Expand All @@ -512,10 +512,15 @@ function linearize_symbolic(sys::AbstractSystem, inputs,

fun_expr = generate_rhs(sys; expression = Val{true})[1]
fun = eval_or_rgf(fun_expr; eval_expression, eval_module)
dx = fun(sts, p, t)


Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

[JuliaFormatter] reported by reviewdog 🐶

Suggested change

h = build_explicit_observed_function(sys, outputs; eval_expression, eval_module)
y = h(sts, p, t)
if split
dx = fun(sts, p, t)
y = h(sts, p, t)
else
dx = fun(sts, p..., t)
y = h(sts, p..., t)
end

fg_xz = Symbolics.jacobian(dx, sts)
fg_u = Symbolics.jacobian(dx, inputs)
Expand Down
2 changes: 2 additions & 0 deletions test/linearize.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -120,7 +120,9 @@ lsys2 = ModelingToolkit.reorder_unknowns(lsys1, unknowns(ssys), desired_order)
@test lsys.D[] == lsys2.D[] == 0

## Symbolic linearization
lsyss_ns, ssys_ns = ModelingToolkit.linearize_symbolic(cl, [f.u], [p.x], split=false)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

[JuliaFormatter] reported by reviewdog 🐶

Suggested change
lsyss_ns, ssys_ns = ModelingToolkit.linearize_symbolic(cl, [f.u], [p.x], split=false)
lsyss_ns, ssys_ns = ModelingToolkit.linearize_symbolic(cl, [f.u], [p.x], split = false)

lsyss, ssys = ModelingToolkit.linearize_symbolic(cl, [f.u], [p.x])
@test isequal(lsyss.A, lsyss_ns.A)

lsyss = ModelingToolkit.reorder_unknowns(lsyss, unknowns(ssys), [f.x, p.x])
@test ModelingToolkit.fixpoint_sub(lsyss.A, ModelingToolkit.defaults(cl)) == lsys.A
Expand Down
Loading