fix sankey trace x/y node fields

Closes #308

Signed-off-by: Andrei Gherghescu <8067229+andrei-ng@users.noreply.github.com>

Author: andrei-ng

docs/book/src/recipes/basic_charts/sankey_diagrams.md

@@ -15,114 +15,16 @@ use rand_distr::{Distribution, Normal, Uniform};
 The `to_inline_html` method is used to produce the html plot displayed in this page.
 
 ## Constructing a basic Sankey diagram
-```rust
-let trace = Sankey::new()
-        .orientation(Orientation::Horizontal)
-        .node(
-            Node::new()
-                .pad(15)
-                .thickness(30)
-                .line(SankeyLine::new().color(NamedColor::Black).width(0.5))
-                .label(vec!["A1", "A2", "B1", "B2", "C1", "C2"])
-                .color_array(vec![
-                    NamedColor::Blue,
-                    NamedColor::Blue,
-                    NamedColor::Blue,
-                    NamedColor::Blue,
-                    NamedColor::Blue,
-                    NamedColor::Blue,
-                ]),
-        )
-        .link(
-            Link::new()
-                .value(vec![8, 4, 2, 8, 4, 2])
-                .source(vec![0, 1, 0, 2, 3, 3])
-                .target(vec![2, 3, 3, 4, 4, 5]),
-        );
+```rust,no_run
+{{#include ../../../../../examples/basic_charts/src/main.rs:basic_sankey_diagram}}
+```
 
-    let layout = Layout::new()
-        .title("Basic Sankey".into())
-        .font(Font::new().size(10));
+{{#include ../../../../../examples/basic_charts/output/inline_basic_sankey_diagram.html}}
 
-    let mut plot = Plot::new();
-    plot.add_trace(trace);
-    plot.set_layout(layout);
 
-    if show {
-        plot.show();
-    }
-}
+## Skankey diagram with defined node position
+```rust,no_run
+{{#include ../../../../../examples/basic_charts/src/main.rs:custom_node_sankey_diagram}}
 ```
-<div id="basic-sankey-diagram" class="plotly-graph-div" style="height:100%; width:100%;"></div>
-<script type="text/javascript">
-    window.PLOTLYENV=window.PLOTLYENV || {};
-    if (document.getElementById("basic-sankey-diagram")) {
-        Plotly.newPlot('basic-sankey-diagram', {
-  "data": [
-    {
-      "type": "sankey",
-      "orientation": "h",
-      "node": {
-        "color": [
-          "blue",
-          "blue",
-          "blue",
-          "blue",
-          "blue",
-          "blue"
-        ],
-        "label": [
-          "A1",
-          "A2",
-          "B1",
-          "B2",
-          "C1",
-          "C2"
-        ],
-        "line": {
-          "color": "black",
-          "width": 0.5
-        },
-        "pad": 15,
-        "thickness": 30
-      },
-      "link": {
-        "source": [
-          0,
-          1,
-          0,
-          2,
-          3,
-          3
-        ],
-        "target": [
-          2,
-          3,
-          3,
-          4,
-          4,
-          5
-        ],
-        "value": [
-          8,
-          4,
-          2,
-          8,
-          4,
-          2
-        ]
-      }
-    }
-  ],
-  "layout": {
-    "title": {
-      "text": "Basic Sankey"
-    },
-    "font": {
-      "size": 10
-    }
-  },
-  "config": {}
-});
-    };
-</script>
+
+{{#include ../../../../../examples/basic_charts/output/inline_custom_node_sankey_diagram.html}}

examples/basic_charts/src/main.rs

@@ -810,6 +810,44 @@ fn basic_sankey_diagram(show: bool, file_name: &str) {
 }
 // ANCHOR_END: basic_sankey_diagram
 
+// ANCHOR: custom_node_sankey_diagram
+fn custom_node_sankey_diagram(show: bool, file_name: &str) {
+    // https://plotly.com/javascript/sankey-diagram/#basic-sankey-diagram
+    let trace = Sankey::new()
+        .orientation(Orientation::Horizontal)
+        .arrangement(plotly::sankey::Arrangement::Snap)
+        .node(
+            Node::new()
+                .pad(15)
+                .thickness(30)
+                .line(SankeyLine::new().color(NamedColor::Black).width(0.5))
+                .label(vec!["A", "B", "C", "D", "E", "F"])
+                .x(vec![0.2, 0.1, 0.5, 0.7, 0.3, 0.5])
+                .y(vec![0.2, 0.1, 0.5, 0.7, 0.3, 0.5])
+                .pad(20),
+        )
+        .link(
+            Link::new()
+                .source(vec![0, 0, 1, 2, 5, 4, 3, 5])
+                .target(vec![5, 3, 4, 3, 0, 2, 2, 3])
+                .value(vec![1, 2, 1, 1, 1, 1, 1, 2]),
+        );
+
+    let layout = Layout::new()
+        .title("Define Node Position")
+        .font(Font::new().size(10));
+
+    let mut plot = Plot::new();
+    plot.add_trace(trace);
+    plot.set_layout(layout);
+
+    let path = write_example_to_html(&plot, file_name);
+    if show {
+        plot.show_html(path);
+    }
+}
+// ANCHOR_END: custom_node_sankey_diagram
+
 // ANCHOR: table_chart
 fn table_chart(show: bool, file_name: &str) {
     let trace = Table::new(
@@ -1006,6 +1044,7 @@ fn main() {
 
     // Sankey Diagrams
     basic_sankey_diagram(false, "basic_sankey_diagram");
+    custom_node_sankey_diagram(false, "custom_node_sankey_diagram");
 
     // Pie Charts
     basic_pie_chart(false, "basic_pie_chart");

plotly/src/traces/sankey.rs

@@ -59,10 +59,14 @@ pub struct Node {
     hover_template: Option<Dim<String>>,
     label: Option<Vec<String>>,
     line: Option<Line>,
+    /// Sets the padding (in px) between the `nodes`.
     pad: Option<usize>,
+    /// Sets the thickness (in px) of the `nodes`.
     thickness: Option<usize>,
-    x: Option<f64>,
-    y: Option<f64>,
+    /// The normalized horizontal position of the node.
+    x: Option<Vec<f64>>,
+    /// The normalized vertical position of the node.
+    y: Option<Vec<f64>>,
 }
 
 impl Node {
@@ -115,12 +119,12 @@ impl Node {
         self
     }
 
-    pub fn x(mut self, x: f64) -> Self {
+    pub fn x(mut self, x: Vec<f64>) -> Self {
         self.x = Some(x);
         self
     }
 
-    pub fn y(mut self, y: f64) -> Self {
+    pub fn y(mut self, y: Vec<f64>) -> Self {
         self.y = Some(y);
         self
     }
@@ -509,8 +513,8 @@ mod tests {
             .line(Line::new())
             .pad(5)
             .thickness(10)
-            .x(0.5)
-            .y(0.25);
+            .x(vec![0.5])
+            .y(vec![0.25]);
         let expected = json!({
             "color": ["blue"],
             "hoverinfo": "all",
@@ -519,8 +523,8 @@ mod tests {
             "line": {},
             "pad": 5,
             "thickness": 10,
-            "x": 0.5,
-            "y": 0.25
+            "x": [0.5],
+            "y": [0.25]
         });
 
         assert_eq!(to_value(node).unwrap(), expected)