raise TypeError("Cannot convert expression to float") when assigning SymPy expression to an array

[xiang-yu]

julia> @syms x, y julia> xx = zeros(2,2) julia> xx[1, 1] = x*y ERROR: PyError (ccall(#= /Users/lixi307/.julia/packages/PyCall/ygXW2/src/conversions.jl:59 =# @pysym(:PyFloat_AsDouble), Cdouble, (PyPtr,), po)) <class 'TypeError'> TypeError('Cannot convert expression to float')

If I define "xx" in type "Any" xx = Array{Any}(undef, 2,2) julia> xx[1, 1] = x*y x⋅y

However, I need a zeros instead of "undef". How to initialise a zero symbolic array using SymPy.jl?

[mzaffalon]

You should use zeros(Sym,2,2):

julia> @syms x, y
(x, y)

julia> xx = zeros(Sym,2,2);

julia> xx[1, 1] = x*y
x⋅y

[xiang-yu]

Thanks. It works well.

[mzaffalon]

This issue can be closed.