diff --git a/ext/opencv/algorithm.cpp b/ext/opencv/algorithm.cpp
index a406366..837a1da 100644
--- a/ext/opencv/algorithm.cpp
+++ b/ext/opencv/algorithm.cpp
@@ -27,7 +27,7 @@ rb_class()
 VALUE
 rb_set_int(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   try {
     ALGORITHM(self)->setInt(StringValueCStr(parameter), NUM2INT(value));
   }
@@ -41,7 +41,7 @@ rb_set_int(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_set_double(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   try {
     ALGORITHM(self)->setDouble(StringValueCStr(parameter), NUM2DBL(value));
   }
@@ -55,7 +55,7 @@ rb_set_double(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_set_bool(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   try {
     bool val = TRUE_OR_FALSE(value) ? true : false;
     ALGORITHM(self)->setBool(StringValueCStr(parameter), val);
@@ -70,8 +70,8 @@ rb_set_bool(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_set_string(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
-  Check_Type(T_STRING, value);
+  Check_Type(parameter, T_STRING);
+  Check_Type(value, T_STRING);
   try {
     ALGORITHM(self)->setString(StringValueCStr(parameter), StringValueCStr(value));
   }
@@ -85,7 +85,7 @@ rb_set_string(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_set_mat(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   try {
     CvMat* val = CVMAT_WITH_CHECK(value);
     cv::Mat mat(val);
@@ -101,8 +101,8 @@ rb_set_mat(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_set_matvector(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
-  Check_Type(T_ARRAY, value);
+  Check_Type(parameter, T_STRING);
+  Check_Type(value, T_ARRAY);
   try {
     long len = RARRAY_LEN(value);
     VALUE* value_ptr = RARRAY_PTR(value);
@@ -124,7 +124,7 @@ rb_set_matvector(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_set_algorithm(VALUE self, VALUE parameter, VALUE value)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   try {
     ALGORITHM(self)->setAlgorithm(StringValueCStr(parameter), ALGORITHM(value));
   }
@@ -139,7 +139,7 @@ rb_set_algorithm(VALUE self, VALUE parameter, VALUE value)
 VALUE
 rb_get_int(VALUE self, VALUE parameter)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   int value = 0;
   try {
     value = ALGORITHM(self)->getInt(StringValueCStr(parameter));
@@ -154,7 +154,7 @@ rb_get_int(VALUE self, VALUE parameter)
 VALUE
 rb_get_double(VALUE self, VALUE parameter)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   double value = 0.0;
   try {
     value = ALGORITHM(self)->getDouble(StringValueCStr(parameter));
@@ -163,13 +163,13 @@ rb_get_double(VALUE self, VALUE parameter)
     raise_cverror(e);
   }
 
-  return NUM2DBL(value);
+  return DBL2NUM(value);
 }
 
 VALUE
 rb_get_bool(VALUE self, VALUE parameter)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   bool value = false;
   try {
     value = ALGORITHM(self)->getBool(StringValueCStr(parameter));
@@ -184,7 +184,7 @@ rb_get_bool(VALUE self, VALUE parameter)
 VALUE
 rb_get_string(VALUE self, VALUE parameter)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   std::string value = "";
   try {
     value = ALGORITHM(self)->getString(StringValueCStr(parameter));
@@ -217,7 +217,7 @@ rb_get_mat(VALUE self, VALUE parameter)
 VALUE
 rb_get_matvector(VALUE self, VALUE parameter)
 {
-  Check_Type(T_STRING, parameter);
+  Check_Type(parameter, T_STRING);
   VALUE array = Qnil;
   try {
     std::vector<cv::Mat> value = ALGORITHM(self)->getMatVector(StringValueCStr(parameter));
diff --git a/test/test_lbph.rb b/test/test_lbph.rb
index 4ff107b..64b818b 100755
--- a/test/test_lbph.rb
+++ b/test/test_lbph.rb
@@ -25,19 +25,15 @@ class TestLBPH < OpenCVTestCase
     assert_raise(TypeError) {
       LBPH.new(DUMMY_OBJ)
     }
-
     assert_raise(TypeError) {
       LBPH.new(1, DUMMY_OBJ)
     }
-
     assert_raise(TypeError) {
       LBPH.new(1, 2, DUMMY_OBJ)
     }
-
     assert_raise(TypeError) {
       LBPH.new(1, 2, 3, DUMMY_OBJ)
     }
-
     assert_raise(TypeError) {
       LBPH.new(1, 2, 3, 4, DUMMY_OBJ)
     }
@@ -88,5 +84,66 @@ class TestLBPH < OpenCVTestCase
   def test_name
     assert_equal('FaceRecognizer.LBPH', @lbph.name)
   end
+
+  def test_get_int
+    assert_equal(1, @lbph.get_int('radius'))
+    assert_equal(8, @lbph.get_int('neighbors'))
+    assert_equal(8, @lbph.get_int('grid_x'))
+    assert_equal(8, @lbph.get_int('grid_y'))
+
+    assert_raise(TypeError) {
+      @lbph.get_int(DUMMY_OBJ)
+    }
+  end
+
+  def test_get_double
+    assert_equal(Float::MAX, @lbph.get_double('threshold'))
+
+    assert_raise(TypeError) {
+      @lbph.get_double(DUMMY_OBJ)
+    }
+  end
+
+  def test_get_matvector
+    histgrams = @lbph_trained.get_matvector('histograms')
+    assert_equal(Array, histgrams.class)
+    assert_equal(2, histgrams.size)
+    assert_equal(CvMat, histgrams[0].class)
+
+    assert_raise(TypeError) {
+      @lbph.get_matvector(DUMMY_OBJ)
+    }
+  end
+
+  def test_set_int
+    @lbph.set_int('radius', 2)
+    @lbph.set_int('neighbors', 3)
+    @lbph.set_int('grid_x', 4)
+    @lbph.set_int('grid_y', 5)
+
+    assert_equal(2, @lbph.get_int('radius'))
+    assert_equal(3, @lbph.get_int('neighbors'))
+    assert_equal(4, @lbph.get_int('grid_x'))
+    assert_equal(5, @lbph.get_int('grid_y'))
+
+    assert_raise(TypeError) {
+      @lbph.set_int(DUMMY_OBJ, 1)
+    }
+    assert_raise(TypeError) {
+      @lbph.set_int('radius', DUMMY_OBJ)
+    }
+  end
+
+  def test_set_double
+    @lbph.set_double('threshold', 1.0)
+    assert_in_delta(1.0, @lbph.get_double('threshold'), 0.001)
+
+    assert_raise(TypeError) {
+      @lbph.set_double(DUMMY_OBJ, 1.0)
+    }
+    assert_raise(TypeError) {
+      @lbph.set_double('threshold', DUMMY_OBJ)
+    }
+  end
 end