Remove duplicate implementation of block diag matrices

src/Matrix.jl

@@ -276,31 +276,7 @@ Create the block diagonal matrix whose blocks are given by the matrices in `V`.
 There must be at least one matrix in V.
 """
 function block_diagonal_matrix(V::Vector{<:MatElem{T}}) where T <: NCRingElement
-   length(V) > 0 || error("At least one matrix is required")
-   rows = sum(nrows(N) for N in V)
-   cols = sum(ncols(N) for N in V)
-   R = base_ring(V[1])
-   M = similar(V[1], rows, cols)
-   start_row = 1
-   start_col = 1
-   for i = 1:length(V)
-      end_row = start_row + nrows(V[i]) - 1
-      end_col = start_col + ncols(V[i]) - 1
-      for j = start_row:end_row
-         for k = 1:start_col - 1
-            M[j, k] = zero(R)
-         end
-         for k = start_col:end_col
-            M[j, k] = V[i][j - start_row + 1, k - start_col + 1]
-         end
-         for k = end_col + 1:cols
-            M[j, k] = zero(R)
-         end
-      end
-      start_row = end_row + 1
-      start_col = end_col + 1
-   end
-   return M
+   return diagonal_matrix(V)
 end
 
 @doc raw"""
@@ -310,26 +286,7 @@ Create the block diagonal matrix over the ring `R` whose blocks are given
 by the matrices in `V`. Entries are coerced into `R` upon creation.
 """
 function block_diagonal_matrix(R::NCRing, V::Vector{<:Matrix{T}}) where T <: NCRingElement
-   if length(V) == 0
-      return zero_matrix(R, 0, 0)
-   end
-   rows = sum(size(N)[1] for N in V)
-   cols = sum(size(N)[2] for N in V)
-   M = zero_matrix(R, rows, cols)
-   start_row = 1
-   start_col = 1
-   for i = 1:length(V)
-      end_row = start_row + size(V[i])[1] - 1
-      end_col = start_col + size(V[i])[2] - 1
-      for j = start_row:end_row
-         for k = start_col:end_col
-            M[j, k] = R(V[i][j - start_row + 1, k - start_col + 1])
-         end
-      end
-      start_row = end_row + 1
-      start_col = end_col + 1
-   end
-   return M
+   return diagonal_matrix(R, V)
 end
 
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