From feafd6df36a96d41cb2ad7f9a2aa6c367f044a01 Mon Sep 17 00:00:00 2001
From: Chris Watson <chris@watzon.me>
Date: Tue, 18 Jun 2019 00:13:49 -0700
Subject: [PATCH] Added each_row and each_column to Matrix

---
 src/apatite/linear_algebra/matrix.cr | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/apatite/linear_algebra/matrix.cr b/src/apatite/linear_algebra/matrix.cr
index 9cc4bd8..52d8bc5 100644
--- a/src/apatite/linear_algebra/matrix.cr
+++ b/src/apatite/linear_algebra/matrix.cr
@@ -313,6 +313,20 @@ module Apatite::LinearAlgebra
     #   Matrix.combine(self, matrices, &block)
     # end
 
+    # Iterates over each column, yielding the column
+    def each_column(&block)
+      vectors = column_vectors.map { |vec| yield(vec) }
+      @buffer = Matrix.columns(vectors).to_unsafe
+      vectors
+    end
+
+    # Iterates over each row, yielding the row
+    def each_row(&block)
+      vectors = rows.map { |vec| yield(vec) }
+      @buffer = Matrix.rows(vectors).to_unsafe
+      vectors
+    end
+
     # # Hadamard product
     # def hadamard_product(m)
     #   combine(m){|a, b| a * b}
@@ -496,7 +510,7 @@ module Apatite::LinearAlgebra
     end
 
     def row(i, &block)
-      @rows.fetch(i) { return self }.each(&block)
+      rows.fetch(i) { return self }.each(&block)
       self
     end
 
@@ -550,6 +564,10 @@ module Apatite::LinearAlgebra
       end
     end
 
+    def to_unsafe
+      @buffer
+    end
+
     @[AlwaysInline]
     def unsafe_fetch(index : Int)
       @buffer[index]