diff --git a/stubs/internal/Common.php b/stubs/internal/Common.php
index fc939f2..25bb6a1 100644
--- a/stubs/internal/Common.php
+++ b/stubs/internal/Common.php
@@ -100,4 +100,42 @@ interface Common
      * @return void
      */
     function copySize($other);
+
+    /**
+     * For all elements equal to $old_value, set them to $new_value.
+     *
+     * For SpMat, replacement is not done when $old_value == 0.
+     *
+     * @param number|\Arma\Complex $old_value
+     * @param number|\Arma\Complex $new_value
+     * @return void
+     */
+    function replace($old_value, $new_value);
+
+    /**
+     * Transform each element using a callback function.
+     *
+     * Transformation is done column-by-column, and for SpMat only non-zero elements will be transformed.
+     *
+     * @param callable $callback ($old_value) => $new_value
+     * @return void
+     */
+    function transform($callback);
+
+    /**
+     * For each element, pass its reference to a callback function.
+     *
+     * Processing is done column-by-column, and for SpMat only non-zero elements will be passed to callback.
+     *
+     * @param callable $callback
+     * @return void
+     */
+    function forEach($callback);
+
+    /**
+     * Reset the size to zero. The object will have no elements.
+     *
+     * @return void
+     */
+    function reset();
 }
diff --git a/stubs/internal/Dense.php b/stubs/internal/Dense.php
index 91b9502..a37f9be 100644
--- a/stubs/internal/Dense.php
+++ b/stubs/internal/Dense.php
@@ -67,9 +67,10 @@ interface Dense extends Common
     function notSmallerThan($other);
 
     /**
-     * Sets the elements to a specified value.
+     * Sets the elements to a specified value. The type of value must match the type of elements used by
+     * the container object.
      *
-     * The type of value must match the type of elements used by the container object.
+     * For matrices, filling is done column-by-column.
      *
      * @param number|\Arma\Complex $value
      * @return void
@@ -77,11 +78,11 @@ interface Dense extends Common
     function fill($value);
 
     /**
-     * Fill with values provided by a functor or lambda function.
+     * Fill with values provided by a callback function.
      *
      * For matrices, filling is done column-by-column.
      *
-     * @param callable $callback
+     * @param callable $callback () => $fill_value
      * @return void
      */
     function imbue($callback);