can create from arrays

matrix/Cargo.toml

@@ -8,3 +8,4 @@ edition = "2018"
 
 [dependencies]
 approx = "0.4"
+bencher = "0.1.5"

matrix/src/lib.rs

@@ -14,6 +14,20 @@ impl Matrix {
             matrix: matrix,
         }
     }
+
+    pub fn from_array(matrix: [[f32; 4]; 4]) -> Matrix {
+        let mut m = Vec::with_capacity(4);
+        for row in 0..matrix.len() {
+            let mut r = Vec::with_capacity(4);
+            for col in 0..matrix[row].len() {
+                r.push(matrix[row][col]);
+            }
+            m.push(r);
+        }
+        Matrix {
+            matrix: m,
+        }
+    }
 }
 
 impl Index<usize> for Matrix {
@@ -66,6 +80,25 @@ mod tests {
         assert_eq!(15.5,  matrix[3][2]);
     }
 
+    #[test]
+    fn matrix_4x4_array() {
+        let m = [
+            [1.0, 2.0, 3.0, 4.0],
+            [5.5, 6.5, 7.5, 8.5],
+            [9.0, 10.0, 11.0, 12.0],
+            [13.5, 14.5, 15.5, 16.5],
+        ];
+
+        let matrix = Matrix::from_array(m);
+        assert_eq!(1.0, matrix[0][0]);
+        assert_eq!(4.0, matrix[0][3]);
+        assert_eq!(5.5, matrix[1][0]);
+        assert_eq!(7.5, matrix[1][2]);
+        assert_eq!(11.0, matrix[2][2]);
+        assert_eq!(13.5,  matrix[3][0]);
+        assert_eq!(15.5,  matrix[3][2]);
+    }
+
     #[test]
     fn matrix_2x2() {
         let m = vec![