diff --git a/Cargo.lock b/Cargo.lock
index aded64e..b71dedc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -729,7 +729,7 @@ dependencies = [
 
 [[package]]
 name = "egui_graphs"
-version = "0.0.12"
+version = "0.0.13"
 dependencies = [
  "egui",
  "petgraph",
diff --git a/Cargo.toml b/Cargo.toml
index f83bd8f..69d7dff 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "egui_graphs"
-version = "0.0.12"
+version = "0.0.13"
 authors = ["Dmitrii Samsonov <blitzarx1@gmail.com>"]
 license = "MIT"
 homepage = "https://github.com/blitzarx1/egui_graphs"
diff --git a/example/src/main.rs b/example/src/main.rs
index 838a2ff..56e8fdd 100644
--- a/example/src/main.rs
+++ b/example/src/main.rs
@@ -1,6 +1,7 @@
 use std::{collections::HashMap, time::Instant};
 
 use eframe::{run_native, App, CreationContext};
+use egui::plot::{Line, Plot, PlotPoints};
 use egui::{Context, ScrollArea, Vec2};
 use egui_graphs::{Changes, Edge, Elements, GraphView, Node, Settings};
 use fdg_sim::glam::Vec3;
@@ -21,10 +22,12 @@ pub struct ExampleApp {
 
     selected: Vec<Node>,
 
+    simulation_stopped: bool,
+
+    fps: f64,
+    fps_history: Vec<f64>,
     last_update_time: Instant,
     frames_last_time_span: usize,
-    fps: f32,
-    simulation_stopped: bool,
 }
 
 impl ExampleApp {
@@ -38,10 +41,12 @@ impl ExampleApp {
 
             selected: Default::default(),
 
+            simulation_stopped: false,
+
+            fps: 0.,
+            fps_history: Default::default(),
             last_update_time: Instant::now(),
             frames_last_time_span: 0,
-            fps: 0.,
-            simulation_stopped: false,
         }
     }
 
@@ -103,8 +108,13 @@ impl ExampleApp {
         let elapsed = now.duration_since(self.last_update_time);
         if elapsed.as_secs() >= 1 {
             self.last_update_time = now;
-            self.fps = self.frames_last_time_span as f32 / elapsed.as_secs_f32();
+            self.fps = self.frames_last_time_span as f64 / elapsed.as_secs_f64();
             self.frames_last_time_span = 0;
+
+            self.fps_history.push(self.fps);
+            if self.fps_history.len() > 100 {
+                self.fps_history.remove(0);
+            }
         }
     }
 
@@ -218,6 +228,26 @@ impl App for ExampleApp {
                 egui::TopBottomPanel::bottom("bottom_panel").show_inside(ui, |ui| {
                     ui.add_space(5.);
                     ui.label(format!("fps: {:.1}", self.fps));
+
+                    let sin: PlotPoints = self
+                        .fps_history
+                        .iter()
+                        .enumerate()
+                        .map(|(i, val)| [i as f64, *val])
+                        .collect();
+                    let line = Line::new(sin);
+                    Plot::new("my_plot")
+                        .height(100.)
+                        .show_x(false)
+                        .show_y(false)
+                        .show_background(false)
+                        .show_axes([false, true])
+                        .allow_boxed_zoom(false)
+                        .allow_double_click_reset(false)
+                        .allow_drag(false)
+                        .allow_scroll(false)
+                        .allow_zoom(false)
+                        .show(ui, |plot_ui| plot_ui.line(line));
                 });
             });
 
diff --git a/src/changes.rs b/src/changes.rs
index 5645920..b1c7199 100644
--- a/src/changes.rs
+++ b/src/changes.rs
@@ -73,7 +73,7 @@ impl Changes {
     }
 }
 
-/// stores deltas to the nodes properties
+/// stores changes to the node properties
 #[derive(Default, Clone)]
 pub struct ChangesNode {
     pub location: Option<Vec2>,
@@ -104,7 +104,7 @@ impl ChangesNode {
     }
 }
 
-/// stores deltas to the edges properties
+/// stores changes to the edge properties
 #[derive(Default, Clone)]
 pub struct ChangesEdge {
     pub color: Option<Color32>,
diff --git a/src/elements.rs b/src/elements.rs
index 96f2378..efdcf3e 100644
--- a/src/elements.rs
+++ b/src/elements.rs
@@ -2,9 +2,11 @@ use std::collections::HashMap;
 
 use egui::{Color32, Vec2};
 
+/// Elements represents the collection of all nodes and edges in a graph.
+/// It is passed to the GraphView widget and is used to draw the graph.
 pub struct Elements {
-    pub(crate) nodes: HashMap<usize, Node>,
-    pub(crate) edges: HashMap<(usize, usize), Vec<Edge>>,
+    nodes: HashMap<usize, Node>,
+    edges: HashMap<(usize, usize), Vec<Edge>>,
 }
 
 impl Elements {
@@ -12,6 +14,33 @@ impl Elements {
         Self { nodes, edges }
     }
 
+    pub fn get_node(&self, idx: &usize) -> Option<&Node> {
+        self.nodes.get(idx)
+    }
+
+    pub fn get_nodes(&self) -> &HashMap<usize, Node> {
+        &self.nodes
+    }
+
+    pub fn get_edges(&self) -> &HashMap<(usize, usize), Vec<Edge>> {
+        &self.edges
+    }
+
+    pub fn get_edge(&self, idx: &(usize, usize, usize)) -> Option<&Edge> {
+        self.edges.get(&(idx.0, idx.1))?.get(idx.2)
+    }
+
+    /// deletes node and all edges connected to it
+    pub fn delete_node(&mut self, idx: &usize) {
+        self.nodes.remove(idx);
+        self.edges.retain(|k, _| k.0 != *idx && k.1 != *idx);
+    }
+
+    /// deletes edge
+    pub fn delete_edge(&mut self, idx: &(usize, usize, usize)) {
+        self.edges.get_mut(&(idx.0, idx.1)).unwrap().remove(idx.2);
+    }
+
     pub fn get_node_mut(&mut self, idx: &usize) -> Option<&mut Node> {
         self.nodes.get_mut(idx)
     }
diff --git a/src/graph_view.rs b/src/graph_view.rs
index 3c57887..75d5648 100644
--- a/src/graph_view.rs
+++ b/src/graph_view.rs
@@ -48,6 +48,9 @@ impl<'a> GraphView<'a> {
         self.changes.borrow().clone()
     }
 
+    /// should be called to clear cached graph metadata, for example
+    /// in case when you want to show completely different graph from the one
+    /// in the last frame
     pub fn reset_state(ui: &mut Ui) {
         State::default().store(ui);
     }
@@ -96,7 +99,7 @@ fn get_bounds(elements: &Elements) -> (Vec2, Vec2) {
     let mut max_x = MIN;
     let mut max_y = MIN;
 
-    elements.nodes.iter().for_each(|(_, n)| {
+    elements.get_nodes().iter().for_each(|(_, n)| {
         if n.location.x < min_x {
             min_x = n.location.x;
         };
@@ -122,13 +125,13 @@ fn rotate_vector(vec: Vec2, angle: f32) -> Vec2 {
 
 fn draw(p: &Painter, elements: &Elements, zoom: f32, pan: Vec2) {
     draw_edges(p, elements, zoom, pan);
-    draw_nodes(p, &elements.nodes, zoom, pan);
+    draw_nodes(p, elements, zoom, pan);
 }
 
 fn draw_edges(p: &Painter, elements: &Elements, zoom: f32, pan: Vec2) {
     let angle = std::f32::consts::TAU / 50.;
 
-    elements.edges.iter().for_each(|(_, edges)| {
+    elements.get_edges().iter().for_each(|(_, edges)| {
         let edges_count = edges.len();
         let mut sames = HashMap::with_capacity(edges_count);
 
@@ -136,13 +139,11 @@ fn draw_edges(p: &Painter, elements: &Elements, zoom: f32, pan: Vec2) {
             let edge = e.screen_transform(zoom);
 
             let start_node = elements
-                .nodes
-                .get(&edge.start)
+                .get_node(&edge.start)
                 .unwrap()
                 .screen_transform(zoom, pan);
             let end_node = elements
-                .nodes
-                .get(&edge.end)
+                .get_node(&edge.end)
                 .unwrap()
                 .screen_transform(zoom, pan);
 
@@ -235,8 +236,8 @@ fn draw_edges(p: &Painter, elements: &Elements, zoom: f32, pan: Vec2) {
     });
 }
 
-fn draw_nodes(p: &Painter, nodes: &HashMap<usize, Node>, zoom: f32, pan: Vec2) {
-    nodes.iter().for_each(|(_, n)| {
+fn draw_nodes(p: &Painter, elements: &Elements, zoom: f32, pan: Vec2) {
+    elements.get_nodes().iter().for_each(|(_, n)| {
         let node = n.screen_transform(zoom, pan);
         draw_node(p, &node)
     });
@@ -324,9 +325,10 @@ fn handle_zoom_and_pan(ui: &Ui, response: &Response, state: &State) -> (f32, Vec
     (new_zoom, new_pan)
 }
 
-// TODO: optimize this full scan run
+// TODO: optimize this full scan run with quadtree or similar
+// need to modify `crate::elements::Elements` to store nodes in a quadtree
 fn node_by_pos<'a>(elements: &'a Elements, state: &State, pos: Pos2) -> Option<(usize, &'a Node)> {
-    let node_props = elements.nodes.iter().find(|(_, n)| {
+    let node_props = elements.get_nodes().iter().find(|(_, n)| {
         let node = n.screen_transform(state.zoom, state.pan);
         (node.location - pos.to_vec2()).length() <= node.radius
     });
@@ -346,14 +348,14 @@ fn handle_drags(
 ) {
     if response.drag_started() {
         if let Some((idx, _)) = node_by_pos(elements, state, response.hover_pos().unwrap()) {
-            changes.select_node(&idx, elements.nodes.get(&idx).unwrap());
+            changes.select_node(&idx, elements.get_node(&idx).unwrap());
             state.set_dragged_node(idx);
         }
     }
 
     if response.dragged() && state.get_dragged_node().is_some() {
         let node_idx_dragged = state.get_dragged_node().unwrap();
-        let node_dragged = elements.nodes.get(&node_idx_dragged).unwrap();
+        let node_dragged = elements.get_node(&node_idx_dragged).unwrap();
 
         let delta_in_graph_coords = response.drag_delta() / state.zoom;
         changes.move_node(&node_idx_dragged, node_dragged, delta_in_graph_coords);
@@ -361,7 +363,7 @@ fn handle_drags(
 
     if response.drag_released() && state.get_dragged_node().is_some() {
         let idx = &state.get_dragged_node().unwrap();
-        changes.deselect_node(idx, elements.nodes.get(idx).unwrap());
+        changes.deselect_node(idx, elements.get_node(idx).unwrap());
         state.unset_dragged_node();
     }
 }
@@ -378,16 +380,17 @@ fn handle_clicks(
 
     let node = node_by_pos(elements, state, response.hover_pos().unwrap());
     if node.is_none() {
-        elements.nodes.iter().for_each(|(idx, n)| {
+        // TODO: optimize this. keep selected nodes in state to quickly manage them
+        elements.get_nodes().iter().for_each(|(idx, n)| {
             if !n.selected {
                 return;
             }
 
-            changes.deselect_node(idx, elements.nodes.get(idx).unwrap());
+            changes.deselect_node(idx, n);
         });
         return;
     }
 
-    let (idx, _) = node.unwrap();
-    changes.select_node(&idx, elements.nodes.get(&idx).unwrap());
+    let (idx, n) = node.unwrap();
+    changes.select_node(&idx, n);
 }