# Symbolic (symmetric-toepltiz)matrix-vector multiplication doesn't work for higher dimensions of matrix

**URL:** <https://discourse.julialang.org/t/symbolic-symmetric-toepltiz-matrix-vector-multiplication-doesnt-work-for-higher-dimensions-of-matrix/102270>\
**Category:** General Usage\
**Tags:** linearalgebra, symbolics\
**Created:** [July 30, 2023, 2:50pm UTC](https://discourse.julialang.org/t/symbolic-symmetric-toepltiz-matrix-vector-multiplication-doesnt-work-for-higher-dimensions-of-matrix/102270 "2023-07-30T14:50:07Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![yewalenikhil65](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yewalenikhil65/32/26873_2.png) [@yewalenikhil65](https://discourse.julialang.org/u/yewalenikhil65)\
**Post date:** [July 30, 2023, 2:50pm UTC](https://discourse.julialang.org/t/symbolic-symmetric-toepltiz-matrix-vector-multiplication-doesnt-work-for-higher-dimensions-of-matrix/102270/1 "2023-07-30T14:50:07Z")

</div>

I am trying following , and this works okay!

```julia
using Symbolics, ToeplitzMatrices

N =250

a = Symbolics.variables(:a, 0:N);

b= [1; (1:N).*a[2:end]]

A = SymmetricToeplitz(a)
F_expr = A*b;

```

However, the code fails if i increase the code to N=280

```julia

using Symbolics, ToeplitzMatrices

N =280

a = Symbolics.variables(:a, 0:N);

b= [1; (1:N).*a[2:end]]

A = SymmetricToeplitz(a)
F_expr = A*b;

ERROR: MethodError: no method matching plan_fft!(::Vector{Complex{Num}}, ::UnitRange{Int64})

Closest candidates are:
  plan_fft!(::StridedArray{T, N}, ::Any; flags, timelimit, num_threads) where {T<:Union{ComplexF64, ComplexF32}, N}
   @ FFTW ~/.julia/packages/FFTW/HfEjB/src/fft.jl:786
  plan_fft!(::AbstractArray; kws...)
   @ AbstractFFTs ~/.julia/packages/AbstractFFTs/hJ0Fz/src/definitions.jl:65

Stacktrace:
 [1] plan_fft!(x::Vector{Complex{Num}}; kws::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
   @ AbstractFFTs ~/.julia/packages/AbstractFFTs/hJ0Fz/src/definitions.jl:65
 [2] plan_fft!(x::Vector{Complex{Num}})
   @ AbstractFFTs ~/.julia/packages/AbstractFFTs/hJ0Fz/src/definitions.jl:65
 [3] factorize(A::SymmetricToeplitz{Num, Vector{Num}})
   @ ToeplitzMatrices ~/.julia/packages/ToeplitzMatrices/5gW1c/src/linearalgebra.jl:150
 [4] mul!(y::Vector{Num}, A::SymmetricToeplitz{Num, Vector{Num}}, x::Vector{Num}, α::Bool, β::Bool)
   @ ToeplitzMatrices ~/.julia/packages/ToeplitzMatrices/5gW1c/src/linearalgebra.jl:37
 [5] mul!
   @ ~/software/julia-1.9.2/share/julia/stdlib/v1.9/LinearAlgebra/src/matmul.jl:276 [inlined]
 [6] *(A::SymmetricToeplitz{Num, Vector{Num}}, x::Vector{Num})
   @ LinearAlgebra ~/software/julia-1.9.2/share/julia/stdlib/v1.9/LinearAlgebra/src/matmul.jl:56
 [7] top-level scope
   @ REPL[36]:1

```

I have also posted these issues on Symbolics.jl and ToeplitzMatrices.jl

1. [Symbolic (symmetric-toepltiz)matrix-vector multiplication doesn't work for higher dimensions of matrix · Issue #939 · JuliaSymbolics/Symbolics.jl · GitHub](https://github.com/JuliaSymbolics/Symbolics.jl/issues/939)
2. [Symbolic (symmetric-toepltiz)matrix-vector multiplication doesn't work for higher dimensions of matrix · Issue #109 · JuliaLinearAlgebra/ToeplitzMatrices.jl · GitHub](https://github.com/JuliaLinearAlgebra/ToeplitzMatrices.jl/issues/109)