使用ggplot2在地图上绘制热力图

######*****绘制热力图代码*****#######
interval <- seq(0, 150000, 25000)[-2]                                                                   
#设置价格区间
newpri <- cut(data1$price, interval, labels = F)                                                        
#设置价格为因子类型
newpri <- factor(newpri, levels = 1:5, labels = c("25000", "50000", "75000", "100000", "125000"))       
#设置因子顺序
data1$newpri <- newpri                                                                                  
#添加到数据框中
ggmap(beijing) +
        stat_bin2d(aes(LONG, LAT, fill = newpri), data = data1, size = 0.5, alpha = 0.5) +              #绘制热力图
        labs(title = "北京二手房单价", x = '经度', y = '纬度') +                                        #添加标题
        scale_fill_manual("单价（元）",
                          values = c("#64f830", "#adda30", "#d1b930", "#e89230", "#fa5030"),
                          breaks = c("125000", "100000", "75000", "50000", "25000"))                    #设置热力图渐进颜色