save progress

Author: TorkelE

src/expression_utils.jl

@@ -101,6 +101,31 @@ function is_escaped_expr(expr)
 end
 
 
+# the following function is adapted from SymbolicUtils.jl v.19
+# later on (Spetember 2023) modified by Torkel and Shashi (now assumes input not on polynomial form, which is handled elsewhere, previous version failed in these cases anyway).
+# Copyright (c) 2020: Shashi Gowda, Yingbo Ma, Mason Protter, Julia Computing.
+# MIT license
+"""
+    to_multivariate_poly(polyeqs::AbstractVector{BasicSymbolic{Real}})
+
+Convert the given system of polynomial equations to multivariate polynomial representation.
+For example, this can be used in HomotopyContinuation.jl functions.
+"""
+function to_multivariate_poly(polyeqs::AbstractVector{Symbolics.BasicSymbolic{Real}})
+    @assert length(polyeqs)>=1 "At least one expression must be passed to `multivariate_poly`."
+
+    pvar2sym, sym2term = SymbolicUtils.get_pvar2sym(), SymbolicUtils.get_sym2term()
+    ps = map(polyeqs) do x
+        if istree(x) && operation(x) == (/)
+            error("We should not be able to get here, please contact the package authors.")
+        else
+            PolyForm(x, pvar2sym, sym2term).p
+        end
+    end
+
+    ps
+end
+
 ### Old Stuff ###
 
 #This will be called whenever a function stored in funcdict is called.