feat: add transpose function

mljs · Jun 10, 2017 · c264545 · c264545
1 parent f6a97b6
commit c264545
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diff --git a/src/__tests__/test.js b/src/__tests__/test.js
@@ -35,4 +35,9 @@ describe('Sparse Matrix', () => {
         m = new SparseMatrix([[0, 1], [0, 1]]);
         expect(m.isSymmetric()).toBe(false);
     });
+
+    it('transpose', () => {
+        const matrix1 = new SparseMatrix([[1, 2], [3, 4]]);
+        expect(matrix1.transpose().to2DArray()).toEqual([[1, 3], [2, 4]]);
+    });
 });
diff --git a/src/index.js b/src/index.js
@@ -183,6 +183,18 @@ export class SparseMatrix {
         }
         return this;
     }
+
+    /**
+     * @return {SparseMatrix} - New transposed sparse matrix
+     */
+    transpose() {
+        let trans = new SparseMatrix(this.columns, this.rows, {initialCapacity: this.cardinality});
+        this.forEachNonZero((i, j, value) => {
+            trans.set(j, i, value);
+            return value;
+        });
+        return trans;
+    }
 }
 
 SparseMatrix.prototype.klass = 'Matrix';