diff --git a/example/meshio_ex.cpp b/example/meshio_ex.cpp
deleted file mode 100644
index 8dadf73..0000000
--- a/example/meshio_ex.cpp
+++ /dev/null
@@ -1,110 +0,0 @@
-/********************************************************
- *  ██████╗  ██████╗████████╗██╗
- * ██╔════╝ ██╔════╝╚══██╔══╝██║
- * ██║  ███╗██║        ██║   ██║
- * ██║   ██║██║        ██║   ██║
- * ╚██████╔╝╚██████╗   ██║   ███████╗
- *  ╚═════╝  ╚═════╝   ╚═╝   ╚══════╝
- * Geophysical Computational Tools & Library (GCTL)
- *
- * Copyright (c) 2023  Yi Zhang (yizhang-geo@zju.edu.cn)
- *
- * GCTL is distributed under a dual licensing scheme. You can redistribute 
- * it and/or modify it under the terms of the GNU Lesser General Public 
- * License as published by the Free Software Foundation, either version 2 
- * of the License, or (at your option) any later version. You should have 
- * received a copy of the GNU Lesser General Public License along with this 
- * program. If not, see <http://www.gnu.org/licenses/>.
- * 
- * If the terms and conditions of the LGPL v.2. would prevent you from using 
- * the GCTL, please consider the option to obtain a commercial license for a 
- * fee. These licenses are offered by the GCTL's original author. As a rule, 
- * licenses are provided "as-is", unlimited in time for a one time fee. Please 
- * send corresponding requests to: yizhang-geo@zju.edu.cn. Please do not forget 
- * to include some description of your company and the realm of its activities. 
- * Also add information on how to contact you by electronic and paper mail.
- ******************************************************/
-
-#include "../lib/core.h"
-#include "../lib/io.h"
-
-using namespace gctl;
-
-int main(int argc, char const *argv[]) try
-{
-    mesh_io mshio;
-    mshio.read_gmsh_v2_ascii("tmp/test");
-    mshio.info();
-
-    array<vertex3dc> nodes;
-    array<triangle> tris;
-
-    mshio.select_elements("Bz (pT)", NodeData);
-    mshio.export_selected_to(tris, nodes);
-
-    //meshio_data &d = mshio.get_data("Bz (pT)", NodeData);
-    //array<double> dat = d.val;
-    array<double> dat1 = mshio.get_selected_data("Bx (pT)", NodeData);
-    array<double> dat2 = mshio.get_selected_data("By (pT)", NodeData);
-    array<double> dat3 = mshio.get_selected_data("Bz (pT)", NodeData);
-
-    mesh_io mshio2;
-    mshio2.import_from(tris, nodes);
-    mshio2.add_data("Bx (pT)", dat1, NodeData, OverWrite);
-    mshio2.add_data("By (pT)", dat2, NodeData, OverWrite);
-    mshio2.add_data("Bz (pT)", dat3, NodeData, OverWrite);
-    mshio2.save_gmsh_v2_ascii("tmp");
-    mshio2.info();
-
-/*  
-    mshio.read_tetgen_ascii("tmp/ex1.1");
-    mshio.edit_group(Disable, GeometryTag, 5);
-    mshio.edit_group(GeometryTag, 1, PhysicalTag, 1);
-    mshio.edit_group(GeometryTag, 2, PhysicalTag, 2);
-    mshio.edit_group(GeometryTag, 3, PhysicalTag, 3);
-    mshio.edit_group(GeometryTag, 4, PhysicalTag, 4);
-    mshio.edit_group(GeometryTag, 1, "Boundary");
-    mshio.edit_group(GeometryTag, 2, "Body1");
-    mshio.edit_group(GeometryTag, 3, "Body2");
-    mshio.edit_group(GeometryTag, 4, "Body3");
-    mshio.save_gmsh_v2_ascii("tmp/ex1.1");
-*/
-/*
-    mshio.read_gmsh_v2_ascii("tmp/ex1.1");
-    mshio.convert_tags_to_data(GeometryTag);
-
-    array<double> body_val(mshio.element_size("Body2"), 2.0);
-    mshio.add_element_data("BodyValue", "Body2", body_val);
-
-    array<double> body_val2(mshio.element_size("Body3"), 1.0);
-    mshio.add_element_data("BodyValue", "Body3", body_val2);
-
-    mshio.save_gmsh_v2_ascii("tmp/ex1.2");
-    //mshio.save_vtk_legacy_ascii("tmp/ex1.1");
-    mshio.info();
-
-    const array<vertex3dc> &nodes = mshio.get_nodes();
-
-    array<tetrahedron> body2_tets;
-    mshio.export_elements_to(body2_tets, "All");
-
-    gmshio gio;
-    gio.init_file("tmp.msh", Output);
-    gio.set_packed(NotPacked, Output);
-    gio.save_mesh(body2_tets, nodes);
-*/
-/*
-    mshio.read_gmsh_v2_ascii("tmp/wjb.1");
-    mshio.edit_group(Disable);
-    mshio.edit_group(Enable, GeometryTag, 3);
-    mshio.edit_group(Enable, GeometryTag, 8);
-    mshio.edit_group(Enable, GeometryTag, 9);
-
-    mshio.save_gmsh_v2_ascii("tmp/wjb.2");
-*/
-    return 0;
-}
-catch(std::exception &e)
-{
-    GCTL_ShowWhatError(e.what(), GCTL_ERROR_ERROR, 0, 0, 0);
-}
\ No newline at end of file