szjs/pages/heightSdsCalculator/heightSdsCalculator.js

const app = getApp();
const math = require('../../utils/math.js');

Page({
  data: {
    age: '',
    height: '',
    gender: 'male',
    showResult: false,
    sdsValue: null,
    percentile: null,
    growthEvaluation: '',
    chartData: null
  },

  // 输入年龄
  inputAge(e) {
    this.setData({
      age: Number(e.detail.value) // 确保age是数字
    });
  },

  // 输入身高
  inputHeight(e) {
    this.setData({
      height: Number(e.detail.value) // 确保height是数字
    });
  },

  // 选择性别
  selectGender(e) {
    const gender = e.currentTarget.dataset.gender;
    this.setData({ gender });
  },

  // 重置表单
  reset() {
    this.setData({
      age: '',
      height: '',
      gender: 'male',
      showResult: false
    });
  },

  // 计算SDS
  calculate() {
    const { age, height, gender } = this.data;
    
    // 输入验证
    if (!age || !height) {
      wx.showToast({
        title: '请填写完整信息',
        icon: 'none'
      });
      return;
    }

    // 直接使用本地生长数据
    this.useLocalGrowthData();
  },

  // 处理生长数据
  processGrowthData(growthData) {
    try {
      const { age, height, gender } = this.data;
      
      // 计算SDS值并获取标准数据
      const { sds, standard } = this.calculateSDS(height, age, gender, growthData);
      console.log('SDS计算详情：', {
        height,
        age,
        gender,
        mean: standard.mean,
        sd: standard.sd,
        sds
      });
      
      // 显示计算公式
      console.log(`计算公式：SDS = (${height} - ${standard.mean}) / ${standard.sd} = ${sds.toFixed(2)}`);
      
      // 计算百分位数
      const percentile = this.calculatePercentile(sds);
      
      // 获取生长评价
      const evaluation = this.getGrowthEvaluation(sds);
      
      // 更新结果
      this.setData({
        showResult: true,
        sdsValue: Number(sds.toFixed(2)), // 确保sdsValue是数字类型
        percentile: percentile,
        growthEvaluation: evaluation
      });
      
      // 绘制生长曲线
      this.drawGrowthChart(growthData);
    } catch (error) {
      wx.showToast({
        title: error.message || '计算失败',
        icon: 'none'
      });
    }
  },

  // 使用本地生长数据
  useLocalGrowthData() {
    try {
      const localData = require('./growthData.js');
      // 确保数据类型一致
      const processedData = localData.map(item => ({
        ...item,
        age: Number(item.age)
      }));
      this.processGrowthData(processedData);
    } catch (error) {
      wx.showToast({
        title: '本地数据加载失败',
        icon: 'none'
      });
    }
  },

  // 计算SDS值
  calculateSDS(height, age, gender, growthData) {
    // 根据年龄和性别获取标准值
    const standard = growthData.find(d => 
      Number(d.age) === Number(age) && 
      d.gender === gender
    );
    
    if (!standard) {
      throw new Error('未找到对应年龄和性别的标准数据');
    }
    
    // SDS = (实际值 - 平均值) / 标准差
    const sds = (height - standard.mean) / standard.sd;
    return { sds, standard };
  },

  // 计算百分位数
  calculatePercentile(sds) {
    // 使用标准正态分布计算百分位数
    const percentile = 100 * (1 + math.erf(sds / Math.sqrt(2))) / 2;
    return percentile.toFixed(1);
  },

  // 获取生长评价
  getGrowthEvaluation(sds) {
    if (sds < -2) {
      return '生长迟缓';
    } else if (sds >= -2 && sds <= 2) {
      return '正常范围';
    } else {
      return '生长过快';
    }
  },

  // 绘制生长曲线
  drawGrowthChart(growthData) {
    const ctx = wx.createCanvasContext('growthChart');
    
    // 绘制逻辑...
    
    ctx.draw();
  },

  // 返回
  onClickLeft() {
    wx.navigateBack();
  }
});