refactor: Change dataMinBin to include 0th bin since it can include n…

…on-zero values

src/Histogram.ts

@@ -46,16 +46,15 @@ export default class Histogram {
     this.max = hinfo.max;
     this.binSize = hinfo.binSize;
 
-    // track the first and last nonzero bins with at least 1 sample
-    // TODO: If `this.min` is not 0, should `this.dataMinBin` be `0` (instead of starting at 1)
-    // since the first bin doesn't represent zero values?
-    for (let i = 1; i < this.bins.length; i++) {
+    // TODO: These should always return 0 and NBINS - 1, respectively. Test if these
+    // can be removed.
+    for (let i = 0; i < this.bins.length; i++) {
       if (this.bins[i] > 0) {
         this.dataMinBin = i;
         break;
       }
     }
-    for (let i = this.bins.length - 1; i >= 1; i--) {
+    for (let i = this.bins.length - 1; i >= 0; i--) {
       if (this.bins[i] > 0) {
         this.dataMaxBin = i;
         break;

src/test/lut.test.ts

@@ -14,9 +14,8 @@ describe("test histogram", () => {
   const histogram = new Histogram(conedata);
 
   describe("binary volume data", () => {
-    it("has a min of 255", () => {
-      // histogram dataMin is the min nonzero value
-      expect(histogram.getMin()).to.equal(255);
+    it("has a min of 0", () => {
+      expect(histogram.getMin()).to.equal(0);
     });
     it("has a max of 255", () => {
       expect(histogram.getMax()).to.equal(255);