[从头学数学] 第28节 数据收集整理

剧情提要：
[机器小伟]在[工程师阿伟]的陪同下进入练气期第四层功法的修炼，
这次要修炼的目标是[数据收集整理]。

正剧开始：

星历2016年01月05日 10:17:26, 银河系厄尔斯星球中华帝国江南行省。

[工程师阿伟]正在和[机器小伟]一起进行着数据的收集和整理，这应该是概率论与数理统
计的最初的一节了。

星历2016年01月05日 10:18:50, [工程师阿伟]说：由于以后会有越来越多的地方会用到统
计，所以我就先在这里给你做一个统计类吧，以后有了新的需要可以不断地添加亲函数。[机
器小伟]。

阿伟于是制作了统计类：

<span style="font-size:18px;">/*** @usage   统计类* @author  mw* @date    2016年01月05日  星期二  10:14:34 * @param* @return**/function Statistic() {this.statisticalSample = 0;this.sampleSize = 0;//初始化this.init = function(array) {this.statisticalSample = new Array();this.statisticalSample = array;this.sampleSize = this.statisticalSample.length;}//最大值this.max = function() {var max = Number.NEGATIVE_INFINITY;for (var i = 0; i < this.sampleSize; i++) {if (max < this.statisticalSample[i]) {max = this.statisticalSample[i];}}return max;}//最小值this.min = function() {var min = Number.POSITIVE_INFINITY;for (var i = 0; i < this.sampleSize; i++) {if (min > this.statisticalSample[i]) {min = this.statisticalSample[i];}}return min;}//样本数量this.size = function() {return this.sampleSize;}}</span>

10:19:33, 小伟拿着阿伟给他制作的统计类，开始了数据收集整理的修炼。

这个是小伟对校服的统计。

<span style="font-size:18px;">function myDraw() {plot.init();setPreference();plot.save();plot.translate(50, 350);axis(0, 0, 600);/*统计样本statistical sample统计个数Number of Statistics个数Number长度length*/var sample = [9,6,15,8];var color = ['red', 'yellow', 'blue', '#888888'];var text = ['红色', '黄色', '蓝色', '白色'];var height = 200, width = 300;var stat = new Statistic();stat.init(sample);var max = stat.max();var min = stat.min();var size = stat.size();var perH = Math.floor(height / (max+1));var perW = Math.floor(width / (size*1.5 - 1));var perDiff = -perH;plot.setStrokeStyle('#CCCCCC').setTextAlign('right');for (var i = 0; i < 1.2 * max; i+=5) {if (i > 0) {plot.beginPath().moveTo(0, 0+i * perDiff).lineTo(width+100, 0 + i*perDiff).closePath().stroke();}plot.fillText((i).toFixed(0), -5, i*perDiff, 100);}plot.setTextAlign('left');for (var i = 0; i < size; i++) {plot.setFillStyle(color[i]);plot.fillRect(5+1.5*i*perW, 0, perW, -sample[i]*perH);plot.fillText(text[i], 5+(1.5 * i+0.2) * perW, -(sample[i]+1)*perH, 100);}plot.restore();}</span>

<span style="font-size:18px;">function myDraw() {plot.init();setPreference();plot.save();plot.translate(50, 350);axis(0, 0, 600);/*统计样本statistical sample统计个数Number of Statistics个数Number长度length*/var sample = [15, 12, 4];var color = ['red', 'yellow', 'blue', '#888888'];var text = ['晴天', '阴天', '下雪'];var height = 200, width = 300;var stat = new Statistic();stat.init(sample);var max = stat.max();var min = stat.min();var size = stat.size();var perH = Math.floor(height / (max+1));var perW = Math.floor(width / (size*1.5 - 1));var perDiff = -perH;plot.setStrokeStyle('#CCCCCC').setTextAlign('right');for (var i = 0; i < 1.2 * max; i+=5) {if (i > 0) {plot.beginPath().moveTo(0, 0+i * perDiff).lineTo(width+100, 0 + i*perDiff).closePath().stroke();}plot.fillText((i).toFixed(0), -5, i*perDiff, 100);}plot.setTextAlign('left');for (var i = 0; i < size; i++) {plot.setFillStyle(color[i]);plot.fillRect(5+1.5*i*perW, 0, perW, -sample[i]*perH);plot.fillText(text[i], 5+(1.5 * i+0.2) * perW, -(sample[i]+1)*perH, 100);}plot.restore();}</span>

<span style="font-size:18px;">function myDraw() {plot.init();setPreference();plot.save();plot.translate(50, 350);axis(0, 0, 600);/*统计样本statistical sample统计个数Number of Statistics个数Number长度length*/var sample = [6, 8, 33,12];var color = ['red', 'green', 'blue', '#888888'];var text = ['面包车', '大巴车', '小轿车','摩托车'];var height = 200, width = 300;var stat = new Statistic();stat.init(sample);var max = stat.max();var min = stat.min();var size = stat.size();var perH = Math.floor(height / (max+1));var perW = Math.floor(width / (size*1.5 - 1));var perDiff = -perH;plot.setStrokeStyle('#CCCCCC').setTextAlign('right');for (var i = 0; i < 1.2 * max; i+=5) {if (i > 0) {plot.beginPath().moveTo(0, 0+i * perDiff).lineTo(width+100, 0 + i*perDiff).closePath().stroke();}plot.fillText((i).toFixed(0), -5, i*perDiff, 100);}plot.setTextAlign('left');for (var i = 0; i < size; i++) {plot.setFillStyle(color[i]);plot.fillRect(5+1.5*i*perW, 0, perW, -sample[i]*perH);plot.fillText(text[i], (1.5 * i+0.2) * perW, -(sample[i]+1)*perH, 100);}plot.restore();}</span>

10:34:46, 做了这么多统计，小伟觉得已经掌握了这部分的功法内容。

本节到此结束，欲知后事如何，请看下回分解。