From 068fcb8c8b0d2cf56323a1a235a1f3ed9e49097e Mon Sep 17 00:00:00 2001
From: Andy Zhang <37402126+AnzhiZhang@users.noreply.github.com>
Date: Fri, 9 Aug 2024 17:58:27 +0100
Subject: [PATCH] perf(matrices): update involutory

---
 src/matrices/involutory.jl | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/matrices/involutory.jl b/src/matrices/involutory.jl
index 94dd8dd..0abad47 100644
--- a/src/matrices/involutory.jl
+++ b/src/matrices/involutory.jl
@@ -13,10 +13,11 @@ An involutory matrix is a matrix that is its own inverse.
 """
 struct Involutory{T<:Number} <: AbstractMatrix{T}
     n::Integer
+    M::AbstractMatrix{T}
 
     function Involutory{T}(n::Integer) where {T<:Number}
         n >= 0 || throw(ArgumentError("$n < 0"))
-        return new{T}(n)
+        return new{T}(n, Hilbert{T}(n))
     end
 end
 
@@ -36,7 +37,7 @@ size(A::Involutory) = (A.n, A.n)
 
     # size and hilbert element
     n = T(A.n)
-    element = Hilbert{T}(A.n)[i, j]
+    element = A.M[i, j]
 
     # compute element
     d = -n