2 files changed, 19 insertions, 0 deletions
diff --git a/mllib/src/main/scala/org/apache/spark/mllib/linalg/Matrices.scala b/mllib/src/main/scala/org/apache/spark/mllib/linalg/Matrices.scala
index d1a174063c..3fa5e068d1 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/linalg/Matrices.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/linalg/Matrices.scala
@@ -87,6 +87,9 @@ sealed trait Matrix extends Serializable {
   /** A human readable representation of the matrix */
   override def toString: String = toBreeze.toString()
 
+  /** A human readable representation of the matrix with maximum lines and width */
+  def toString(maxLines: Int, maxLineWidth: Int): String = toBreeze.toString(maxLines, maxLineWidth)
+
   /** Map the values of this matrix using a function. Generates a new matrix. Performs the
     * function on only the backing array. For example, an operation such as addition or
     * subtraction will only be performed on the non-zero values in a `SparseMatrix`. */
diff --git a/mllib/src/test/scala/org/apache/spark/mllib/linalg/MatricesSuite.scala b/mllib/src/test/scala/org/apache/spark/mllib/linalg/MatricesSuite.scala
index 0d2cec58e2..86119ec381 100644
--- a/mllib/src/test/scala/org/apache/spark/mllib/linalg/MatricesSuite.scala
+++ b/mllib/src/test/scala/org/apache/spark/mllib/linalg/MatricesSuite.scala
@@ -439,4 +439,20 @@ class MatricesSuite extends FunSuite {
     assert(mUDT.typeName == "matrix")
     assert(mUDT.simpleString == "matrix")
   }
+
+  test("toString") {
+    val empty = Matrices.ones(0, 0)
+    empty.toString(0, 0)
+
+    val mat = Matrices.rand(5, 10, new Random())
+    mat.toString(-1, -5)
+    mat.toString(0, 0)
+    mat.toString(Int.MinValue, Int.MinValue)
+    mat.toString(Int.MaxValue, Int.MaxValue)
+    var lines = mat.toString(6, 50).lines.toArray
+    assert(lines.size == 5 && lines.forall(_.size <= 50))
+
+    lines = mat.toString(5, 100).lines.toArray
+    assert(lines.size == 5 && lines.forall(_.size <= 100))
+  }
 }