Move update logic out of main code

app.qmd

@@ -23,6 +23,32 @@ maxMu = Math.max(...muValues)
 ```
 
 ```{ojs}
+function updateChartInner(g, x, y, linesGroup, color, line, data) {
+  // Update axes with transitions
+  x.domain([0, d3.max(data, d => d.x)]);
+  g.select(".x-axis").transition().duration(1500).call(d3.axisBottom(x).ticks(10));
+  y.domain([0, d3.max(data, d => d.y)]);
+  g.select(".y-axis").transition().duration(1500).call(d3.axisLeft(y).ticks(5));
+
+  // Group data by basis function
+  const dataByFunction = Array.from(d3.group(data, d => d.b));
+  const keyFn = d => d[0];
+
+  // Update basis function lines
+  const u = linesGroup.selectAll("path").data(dataByFunction, keyFn);
+  u.join(
+    enter => enter.append("path").attr("fill","none").attr("stroke-width",3)
+      .attr("stroke", (_, i) => color(i)).attr("d", d => line(d[1].map(pt => ({x: pt.x, y: 0}))))
+      .style("opacity",0),
+    update => update,
+    exit => exit.transition().duration(1000).style("opacity",0).remove()
+  )
+  .transition().duration(1000)
+    .attr("d", d => line(d[1]))
+    .attr("stroke", (_, i) => color(i))
+    .style("opacity",1);
+}
+
 chart = {
   // State variables for selected parameters
   let selectedMu = 0.5;
@@ -172,43 +198,7 @@ chart = {
    
    // Function to update the chart with new data
    function updateChart(data) {
-     // Update axes with transitions
+     updateChartInner(g, x, y, linesGroup, color, line, data);
-     x.domain([0, d3.max(data, d => d.x)]);
-     g.select(".x-axis")
-       .transition().duration(1500)
-       .call(d3.axisBottom(x).ticks(10));
-     y.domain([0, d3.max(data, d => d.y)]);
-     g.select(".y-axis")
-       .transition().duration(1500)
-       .call(d3.axisLeft(y).ticks(5));
-
-     // Group data by basis function
-     const dataByFunction = Array.from(d3.group(data, d => d.b));
-     
-     // Update the chart title
-    //  svg.select(".chart-title")
-    //    .text(`B-spline Basis Functions (${selectedKnots} knots, μ = ${selectedMu})`);
-     
-     // Create a key function to track basis functions
-     const keyFn = d => d[0];
-     
-     // Update basis function lines with proper enter/update/exit pattern
-     const u = linesGroup.selectAll("path")
-       .data(dataByFunction, keyFn);
-     u.join(
-       enter => enter.append("path")
-         .attr("fill", "none")
-         .attr("stroke-width", 3)
-         .attr("stroke", (_, i) => color(i))
-         .attr("d", d => line(d[1].map(pt => ({x: pt.x, y: 0}))))
-         .style("opacity", 0),
-       update => update,
-       exit => exit.transition().duration(1000).style("opacity", 0).remove()
-     )
-     .transition().duration(1000)
-       .attr("d", d => line(d[1]))
-       .attr("stroke", (_, i) => color(i))
-       .style("opacity", 1);
    }
    
    // Store the update function