From 374554037c764867d63f31bbbcb22ec522d14c51 Mon Sep 17 00:00:00 2001
From: thinkinggis <lzx199065@gmail.com>
Date: Tue, 26 Feb 2019 19:32:09 +0800
Subject: [PATCH] fix(transform): stattistics

---
 .torch.compile.opts.js                |  3 +-
 src/source/transform/hexagon.js       |  3 +
 src/source/transform/statistics.js    | 84 ++++++++++++++++++++++++---
 test/unit/source/transfrom/hexagon.js |  4 +-
 4 files changed, 83 insertions(+), 11 deletions(-)

diff --git a/.torch.compile.opts.js b/.torch.compile.opts.js
index b65d4cd02f..c2e828ddc9 100755
--- a/.torch.compile.opts.js
+++ b/.torch.compile.opts.js
@@ -10,7 +10,8 @@ module.exports = {
   include: [
     'src/**/*.js',
     'test/**/*.js',
-    'node_modules/three/**/*.js'
+    'node_modules/three/**/*.js',
+    'node_modules/simple-statistics/src/*.js'
   ],
   exclude: [
     'node_modules/@babel/**/*.js'
diff --git a/src/source/transform/hexagon.js b/src/source/transform/hexagon.js
index df796c7450..f0aa9692f1 100644
--- a/src/source/transform/hexagon.js
+++ b/src/source/transform/hexagon.js
@@ -27,7 +27,10 @@ export function pointToHexbin(data, option) {
       const columns = getColumn(hex, option.field);
       hex[option.method] = statistics[option.method](columns);
     }
+    const item = {};
+    item[option.method] = hex[option.method];
     return {
+      ...item,
       coordinates: unProjectFlat([ hex.x, hex.y ]),
       id: index + 1
     };
diff --git a/src/source/transform/statistics.js b/src/source/transform/statistics.js
index 2a7a317846..de599d2d41 100644
--- a/src/source/transform/statistics.js
+++ b/src/source/transform/statistics.js
@@ -1,10 +1,76 @@
-/* 支持 'max', 'mean', 'median', 'min', 'mode', 'product', 'standardDeviation',
-   *     'sum', 'sumSimple', 'variance', 'count', 'distinct'
-   */
-export { default as min } from 'simple-statistics/src/min';
-export { default as max } from 'simple-statistics/src/max';
-export { default as mean } from 'simple-statistics/src/mean';
-export { default as sum } from 'simple-statistics/src/sum';
-export { default as median } from 'simple-statistics/src/median';
-export { default as standardDeviation } from 'simple-statistics/src/standard_deviation';
+function max(x) {
+  if (x.length === 0) {
+    throw new Error('max requires at least one data point');
+  }
 
+  let value = x[0];
+  for (let i = 1; i < x.length; i++) {
+    // On the first iteration of this loop, max is
+    // undefined and is thus made the maximum element in the array
+    if (x[i] > value) {
+      value = x[i];
+    }
+  }
+  return value;
+}
+
+function min(x) {
+  if (x.length === 0) {
+    throw new Error('min requires at least one data point');
+  }
+
+  let value = x[0];
+  for (let i = 1; i < x.length; i++) {
+    // On the first iteration of this loop, min is
+    // undefined and is thus made the minimum element in the array
+    if (x[i] < value) {
+      value = x[i];
+    }
+  }
+  return value;
+}
+
+function sum(x) {
+  // If the array is empty, we needn't bother computing its sum
+  if (x.length === 0) {
+    return 0;
+  }
+
+  // Initializing the sum as the first number in the array
+  let sum = x[0];
+
+  // Keeping track of the floating-point error correction
+  let correction = 0;
+
+  let transition;
+
+  for (let i = 1; i < x.length; i++) {
+    transition = sum + x[i];
+
+    // Here we need to update the correction in a different fashion
+    // if the new absolute value is greater than the absolute sum
+    if (Math.abs(sum) >= Math.abs(x[i])) {
+      correction += sum - transition + x[i];
+    } else {
+      correction += x[i] - transition + sum;
+    }
+
+    sum = transition;
+  }
+
+  // Returning the corrected sum
+  return sum + correction;
+}
+function mean(x) {
+  if (x.length === 0) {
+    throw new Error('mean requires at least one data point');
+  }
+  return sum(x) / x.length;
+}
+
+export {
+  sum,
+  max,
+  min,
+  mean
+};
diff --git a/test/unit/source/transfrom/hexagon.js b/test/unit/source/transfrom/hexagon.js
index b0877e7b80..aad4edb018 100644
--- a/test/unit/source/transfrom/hexagon.js
+++ b/test/unit/source/transfrom/hexagon.js
@@ -16,6 +16,8 @@ describe('hexagon  Test', function() {
     const data = {
       dataArray
     };
-    const hexgonGrid = pointToHexbin(data, { size: 100, field: 'count', method: 'sum' });
+    const hexgonGrid = pointToHexbin(data, { size: 100, field: 'v', method: 'sum' });
+    expect(hexgonGrid.dataArray.length).eql(567);
+    console.log(hexgonGrid);
   });
 });