diff --git a/python/pyspark/mllib/linalg/__init__.py b/python/pyspark/mllib/linalg/__init__.py
index 334dc8e38bb8..344b8acc3f86 100644
--- a/python/pyspark/mllib/linalg/__init__.py
+++ b/python/pyspark/mllib/linalg/__init__.py
@@ -461,32 +461,41 @@ def __init__(self, size, *args):
         self.size = int(size)
         """ Size of the vector. """
         assert 1 <= len(args) <= 2, "must pass either 2 or 3 arguments"
-        if len(args) == 1:
-            pairs = args[0]
-            if type(pairs) == dict:
-                pairs = pairs.items()
-            pairs = sorted(pairs)
-            self.indices = np.array([p[0] for p in pairs], dtype=np.int32)
-            """ A list of indices corresponding to active entries. """
-            self.values = np.array([p[1] for p in pairs], dtype=np.float64)
-            """ A list of values corresponding to active entries. """
+        if isinstance(args[0], bytes):
+            assert isinstance(args[1], bytes), "values should be string too"
+            if args[0]:
+                self.indices = np.frombuffer(args[0], np.int32)
+                self.values = np.frombuffer(args[1], np.float64)
+            else:
+                # np.frombuffer() doesn't work well with empty string in older version
+                self.indices = np.array([], dtype=np.int32)
+                self.values = np.array([], dtype=np.float64)
         else:
-            if isinstance(args[0], bytes):
-                assert isinstance(args[1], bytes), "values should be string too"
-                if args[0]:
-                    self.indices = np.frombuffer(args[0], np.int32)
-                    self.values = np.frombuffer(args[1], np.float64)
-                else:
-                    # np.frombuffer() doesn't work well with empty string in older version
-                    self.indices = np.array([], dtype=np.int32)
-                    self.values = np.array([], dtype=np.float64)
+            if len(args) == 1:
+                args = args[0]
+                if isinstance(args, dict):
+                    args = args.items()
+                args = list(zip(*args))
+
+            # Handle empty args case.
+            if len(args) == 0:
+                indices = []
+                values = []
             else:
-                self.indices = np.array(args[0], dtype=np.int32)
-                self.values = np.array(args[1], dtype=np.float64)
-            assert len(self.indices) == len(self.values), "index and value arrays not same length"
-            for i in xrange(len(self.indices) - 1):
-                if self.indices[i] >= self.indices[i + 1]:
-                    raise TypeError("indices array must be sorted")
+                indices, values = args
+
+            """ A list of indices corresponding to active entries. """
+            self.indices = np.array(indices, dtype=np.int32)
+            """ A list of values corresponding to active entries. """
+            self.values = np.array(values, dtype=np.float64)
+
+        indices_length = len(self.indices)
+        values_length = len(self.values)
+        if indices_length != values_length:
+            raise ValueError(
+                "expected values of length %d, got %d." % (indices_length, values_length))
+        if indices_length > self.size:
+            raise ValueError("expected indices length <= %d, got %d" % (self.size, indices_length))
 
     def numNonzeros(self):
         return np.count_nonzero(self.values)