Grid.getHistogram

+ do not exlude any code from main build because it turned off VS Code features in the affected files

src/mol-math/histogram.ts

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2018-2019 mol* contributors, licensed under MIT, See LICENSE file for more info.
+ *
+ * @author Alexander Rose <alexander.rose@weirdbyte.de>
+ */
+
+import { arrayMinMax } from '../mol-util/array';
+
+export interface Histogram {
+    min: number,
+    max: number,
+    binWidth: number,
+    counts: Int32Array
+}
+
+export function calculateHistogram(data: ArrayLike<number>, binCount: number, options?: { min: number, max: number, } ): Histogram {
+    if (!options) {
+        const [min, max] = arrayMinMax(data);
+        return _calcHistogram(data, binCount, min, max);
+    } else {
+        return _calcHistogram(data, binCount, options.min, options.max);
+    }
+}
+
+function _calcHistogram(data: ArrayLike<number>, binCount: number, min: number, max: number): Histogram {
+    let binWidth = (max - min) / binCount;
+    if (binWidth === 0) binWidth = 1;
+
+    const counts = new Int32Array(binCount);
+
+    for (let i = 0, _i = data.length; i < _i; i++) {
+        let bin = Math.floor((data[i] - min) / binWidth);
+        if (bin >= binCount) bin = binCount - 1;
+        else if (bin < 0) bin = 0;
+        counts[bin]++;
+    }
+
+    return { min, max, binWidth, counts };
+}

src/mol-model/volume/grid.ts

@@ -7,6 +7,7 @@
 
 import { SpacegroupCell, Box3D, Sphere3D } from '../../mol-math/geometry';
 import { Tensor, Mat4, Vec3 } from '../../mol-math/linear-algebra';
+import { Histogram, calculateHistogram } from '../../mol-math/histogram';
 
 /** The basic unit cell that contains the grid data. */
 interface Grid {
@@ -60,6 +61,21 @@ namespace Grid {
         const transform = Grid.getGridToCartesianTransform(grid);
         return Sphere3D.fromDimensionsAndTransform(boundingSphere, dimensions, transform);
     }
+
+    /**
+     * Compute histogram with given bin count.
+     * Cached on the Grid object.
+     */
+    export function getHistogram(grid: Grid, binCount: number) {
+        let histograms = (grid as any)._historams as { [binCount: number]: Histogram };
+        if (!histograms) {
+            histograms = (grid as any)._historams = { };
+        }
+        if (!histograms[binCount]) {
+            histograms[binCount] = calculateHistogram(grid.cells.data, binCount, { min: grid.stats.min, max: grid.stats.max });
+        }
+        return histograms[binCount];
+    }
 }
 
 export { Grid };

tsconfig.json

@@ -20,5 +20,5 @@
         "outDir": "lib"
     },
     "include": [ "src/**/*" ],
-    "exclude": [ "src/servers/**/*", "src/perf-tests/*", "src/cli/**/*" ]
+    // "exclude": [ "src/servers/**/*", "src/perf-tests/*", "src/cli/**/*" ]
 }