[SPARK-7176] [ML] Add validation functionality to Param

Main change: Added isValid field to Param.  Modified all usages to use isValid when relevant.  Added helper methods in ParamValidate.

Also overrode Params.validate() in:
* CrossValidator + model
* Pipeline + model

I made a few updates for the elastic net patch:
* I changed "tol" to "convergenceTol"
* I added some documentation

This PR is Scala + Java only.  Python will be in a follow-up PR.

CC: mengxr

Author: Joseph K. Bradley <joseph@databricks.com>

Closes #5740 from jkbradley/enforce-validate and squashes the following commits:

ad9c6c1 [Joseph K. Bradley] re-generated sharedParams after merging with current master
76415e8 [Joseph K. Bradley] reverted convergenceTol to tol
af62f4b [Joseph K. Bradley] Removed changes to SparkBuild, python linalg.  Fixed test failures.  Renamed ParamValidate to ParamValidators.  Removed explicit type from ParamValidators calls where possible.
bb2665a [Joseph K. Bradley] merged with elastic net pr
ecda302 [Joseph K. Bradley] fix rat tests, plus add a little doc
6895dfc [Joseph K. Bradley] small cleanups
069ac6d [Joseph K. Bradley] many cleanups
928fb84 [Joseph K. Bradley] Maybe done
a910ac7 [Joseph K. Bradley] still workin
6d60e2e [Joseph K. Bradley] Still workin
b987319 [Joseph K. Bradley] Partly done with adding checks, but blocking on adding checking functionality to Param
dbc9fb2 [Joseph K. Bradley] merged with master.  enforcing Params.validate

2 files changed, 129 insertions, 0 deletions

diff --git a/mllib/src/test/java/org/apache/spark/ml/param/JavaParamsSuite.java b/mllib/src/test/java/org/apache/spark/ml/param/JavaParamsSuite.java
new file mode 100644
index 0000000000..e7df10dfa6
--- /dev/null
+++ b/mllib/src/test/java/org/apache/spark/ml/param/JavaParamsSuite.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.ml.param;
+
+import com.google.common.collect.Lists;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.apache.spark.api.java.JavaSparkContext;
+
+/**
+ * Test Param and related classes in Java
+ */
+public class JavaParamsSuite {
+
+  private transient JavaSparkContext jsc;
+
+  @Before
+  public void setUp() {
+    jsc = new JavaSparkContext("local", "JavaParamsSuite");
+  }
+
+  @After
+  public void tearDown() {
+    jsc.stop();
+    jsc = null;
+  }
+
+  @Test
+  public void testParams() {
+    JavaTestParams testParams = new JavaTestParams();
+    Assert.assertEquals(testParams.getMyIntParam(), 1);
+    testParams.setMyIntParam(2).setMyDoubleParam(0.4).setMyStringParam("a");
+    Assert.assertEquals(testParams.getMyDoubleParam(), 0.4, 0.0);
+    Assert.assertEquals(testParams.getMyStringParam(), "a");
+  }
+
+  @Test
+  public void testParamValidate() {
+    ParamValidators.gt(1.0);
+    ParamValidators.gtEq(1.0);
+    ParamValidators.lt(1.0);
+    ParamValidators.ltEq(1.0);
+    ParamValidators.inRange(0, 1, true, false);
+    ParamValidators.inRange(0, 1);
+    ParamValidators.inArray(Lists.newArrayList(0, 1, 3));
+    ParamValidators.inArray(Lists.newArrayList("a", "b"));
+  }
+}
diff --git a/mllib/src/test/java/org/apache/spark/ml/param/JavaTestParams.java b/mllib/src/test/java/org/apache/spark/ml/param/JavaTestParams.java
new file mode 100644
index 0000000000..8abe575610
--- /dev/null
+++ b/mllib/src/test/java/org/apache/spark/ml/param/JavaTestParams.java
@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.ml.param;
+
+import java.util.List;
+
+import com.google.common.collect.Lists;
+
+/**
+ * A subclass of Params for testing.
+ */
+public class JavaTestParams extends JavaParams {
+
+  public IntParam myIntParam;
+
+  public int getMyIntParam() { return (Integer)getOrDefault(myIntParam); }
+
+  public JavaTestParams setMyIntParam(int value) {
+    set(myIntParam, value); return this;
+  }
+
+  public DoubleParam myDoubleParam;
+
+  public double getMyDoubleParam() { return (Double)getOrDefault(myDoubleParam); }
+
+  public JavaTestParams setMyDoubleParam(double value) {
+    set(myDoubleParam, value); return this;
+  }
+
+  public Param<String> myStringParam;
+
+  public String getMyStringParam() { return (String)getOrDefault(myStringParam); }
+
+  public JavaTestParams setMyStringParam(String value) {
+    set(myStringParam, value); return this;
+  }
+
+  public JavaTestParams() {
+    myIntParam = new IntParam(this, "myIntParam", "this is an int param", ParamValidators.gt(0));
+    myDoubleParam = new DoubleParam(this, "myDoubleParam", "this is a double param",
+      ParamValidators.inRange(0.0, 1.0));
+    List<String> validStrings = Lists.newArrayList("a", "b");
+    myStringParam = new Param<String>(this, "myStringParam", "this is a string param",
+      ParamValidators.inArray(validStrings));
+    setDefault(myIntParam, 1);
+    setDefault(myDoubleParam, 0.5);
+  }
+}