From 069cda9788032197dfab6ce01e18268d7cd92f53 Mon Sep 17 00:00:00 2001
From: David Hong <hong@udel.edu>
Date: Thu, 29 Feb 2024 23:49:49 -0500
Subject: [PATCH] Avoid making two copies of `K`

1. use `reduce` to compute all but the last `kron`
2. use `kron!` for the last one
---
 src/gcp-opt.jl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/gcp-opt.jl b/src/gcp-opt.jl
index 29c62cb..1995745 100644
--- a/src/gcp-opt.jl
+++ b/src/gcp-opt.jl
@@ -252,7 +252,8 @@ function khatrirao(A::Vararg{T,N}) where {T<:AbstractMatrix,N}
     r = (only ∘ unique)(size.(A, 2))
     K = similar(A[1], prod(size.(A, 1)), r)
     for j in 1:r
-        K[:, j] = reduce(kron, [view(A[i], :, j) for i in 1:N])
+        temp = reduce(kron, [view(A[i], :, j) for i in 1:N-1])
+        kron!(view(K, :, j), temp, view(A[N], :, j))
     end
     return K
 end