diff --git a/dlib/svm/empirical_kernel_map.h b/dlib/svm/empirical_kernel_map.h
index 4ee0cbb3e..b3cea7440 100644
--- a/dlib/svm/empirical_kernel_map.h
+++ b/dlib/svm/empirical_kernel_map.h
@@ -164,6 +164,23 @@ namespace dlib
             return distance_function<kernel_type>(trans(weights)*vect, dot(vect,vect), kernel, vector_to_matrix(basis));
         }
 
+        template <typename EXP>
+        void premultiply_projections_by (
+            const matrix_exp<EXP>& mat
+        )
+        {
+            // make sure requires clause is not broken
+            DLIB_ASSERT(out_vector_size() != 0 && mat.nc() == out_vector_size(),
+                "\t void empirical_kernel_map::premultiply_projections_by()"
+                << "\n\t Invalid inputs to this function."
+                << "\n\t out_vector_size(): " << out_vector_size() 
+                << "\n\t mat.nc():          " << mat.nc() 
+                << "\n\t this: " << this
+                );
+
+            weights = mat*weights;
+        }
+
         const matrix<scalar_type,0,1,mem_manager_type>& project (
             const sample_type& samp
         ) const
diff --git a/dlib/svm/empirical_kernel_map_abstract.h b/dlib/svm/empirical_kernel_map_abstract.h
index e6fe76748..d79753681 100644
--- a/dlib/svm/empirical_kernel_map_abstract.h
+++ b/dlib/svm/empirical_kernel_map_abstract.h
@@ -122,6 +122,20 @@ namespace dlib
                     - returns 0
         !*/
 
+        template <typename EXP>
+        void premultiply_projections_by (
+            const matrix_exp<EXP>& mat
+        );
+        /*!
+            requires
+                - out_vector_size() != 0
+                - mat.nc() == out_vector_size()
+            ensures
+                - #out_vector_size() == mat.nr()
+                - TODO explain what this does.  introduce functions to get the
+                  weights and basis vectors and relate it to those.
+        !*/
+
         const matrix<scalar_type,0,1,mem_manager_type>& project (
             const sample_type& sample 
         ) const;