<attr name="orientation">

            <enum name="horizontal" value="0" />
            <enum name="vertical" value="1" />
        </attr>

dr/src/main/java/com/gzeinnumer/dr/DynamicRadioButton.java

@@ -50,7 +50,7 @@ public <T> DynamicRadioButton setItemList(List<T> items) {
     private <T> void initView(List<T> items) {
         TypedArray attributes = _context.obtainStyledAttributes(_attrs, R.styleable.DynamicCheckBox);
 
-        if (attributes.getInt(R.styleable.DynamicCheckBox_orientation, 1) == 0)
+        if (attributes.getInt(R.styleable.DynamicCheckBox_orientationRadioButton, 1) == 0)
             _orientation = HORIZONTAL;
 
         setOrientation(_orientation);