Add new example

Author: 38

README.md

@@ -122,6 +122,10 @@ To view the source code for each example, please click on the example image.
 	<img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot.svg" class="galleryItem" width=200px></img>
 </a>
 
+<a href="https://github.com/38/plotters/blob/master/examples/3d-plot2.rs">
+	<img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot2.gif" class="galleryItem" width=200px></img>
+</a>
+
 
 ## Table of Contents
   * [Gallery](#gallery)

doc-template/readme/gallery

@@ -92,3 +92,7 @@ To view the source code for each example, please click on the example image.
 <a href="https://github.com/38/plotters/blob/master/examples/3d-plot.rs">
 	<img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot.svg" class="galleryItem" width=200px></img>
 </a>
+
+<a href="https://github.com/38/plotters/blob/master/examples/3d-plot2.rs">
+	<img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot2.gif" class="galleryItem" width=200px></img>
+</a>

doc-template/rustdoc/gallery

@@ -217,3 +217,13 @@
         <a href="https://github.com/38/plotters/blob/master/examples/3d-plot.rs">[code]</a>
     </div>
 </div>
+
+<div class="galleryItem">
+    <a href="https://plotters-rs.github.io/plotters-doc-data/3d-plot2.gif">
+        <img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot2.gif" class="galleryItem"></img>
+    </a>
+    <div class="galleryText">
+		2-Var Gussian Distribution PDF
+        <a href="https://github.com/38/plotters/blob/master/examples/3d-plot2.rs">[code]</a>
+    </div>
+</div>

examples/3d-plot2.rs

@@ -0,0 +1,51 @@
+use plotters::prelude::*;
+fn pdf(x: f64, y: f64) -> f64 {
+    const SDX: f64 = 0.1;
+    const SDY: f64 = 0.1;
+    const A: f64 = 5.0;
+    let x = x as f64 / 10.0;
+    let y = y as f64 / 10.0;
+    A * (-x * x / 2.0 / SDX / SDX - y * y / 2.0 / SDY / SDY).exp()
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let root =
+        BitMapBackend::gif("plotters-doc-data/3d-plot2.gif", (600, 400), 100)?.into_drawing_area();
+
+    for pitch in 0..157 {
+        root.fill(&WHITE)?;
+
+        let mut chart = ChartBuilder::on(&root)
+            .caption("2D Guassian PDF", ("sans-serif", 20))
+            .build_cartesian_3d(-3.0..3.0, 0.0..6.0, -3.0..3.0)?;
+        chart.with_projection(|mut p| {
+            p.pitch = 1.57 - (1.57 - pitch as f64 / 50.0).abs();
+            p.scale = 0.7;
+            p.into_matrix() // build the projection matrix
+        });
+
+        chart.configure_axes().draw()?;
+
+        let series = (-15..15)
+            .map(|x| std::iter::repeat(x).zip(-15..15))
+            .flatten()
+            .map(|(x, z)| {
+                let x = x as f64 / 5.0;
+                let z = z as f64 / 5.0;
+                Polygon::new(
+                    vec![
+                        (x, pdf(x, z), z),
+                        (x + 0.2, pdf(x + 0.2, z), z),
+                        (x + 0.2, pdf(x + 0.2, z + 0.2), z + 0.2),
+                        (x, pdf(x, z + 0.2), z + 0.2),
+                    ],
+                    &HSLColor(240.0 / 360.0 - 240.0 / 360.0 * pdf(x, z) / 5.0, 1.0, 0.7),
+                )
+            });
+
+        chart.draw_series(series)?;
+        root.present()?;
+    }
+
+    Ok(())
+}

plotters-doc-data

@@ -249,6 +249,16 @@ including bitmap, vector graph, piston window, GTK/Cairo and WebAssembly.
     </div>
 </div>
 
+<div class="galleryItem">
+    <a href="https://plotters-rs.github.io/plotters-doc-data/3d-plot2.gif">
+        <img src="https://plotters-rs.github.io/plotters-doc-data/3d-plot2.gif" class="galleryItem"></img>
+    </a>
+    <div class="galleryText">
+        2-Var Gussian Distribution PDF
+        <a href="https://github.com/38/plotters/blob/master/examples/3d-plot2.rs">[code]</a>
+    </div>
+</div>
+
 
 ## Table of Contents
   * [Gallery](#gallery)