假设我想证明1d12 (十二边模)服从矩形分布,2d6服从正态分布。
快速和肮脏的方法是统计大约1000个随机生成的数字,将它们放在一个数组中,然后从那里计算平均值和期望值。
但是,如果我想通过使用运行的总计而不是1000个成员数组来节省内存呢?
我可以这样做吗?
for (i =0; i < 1000; i++){
x = Math.Random(1,6);
runningTotal += x;
}
mean = runningTotal / 1000;
请描述您的问题
标题:腾讯云云产品新购特惠,五折上云!
地址:https://cloud.tencent.com/act/first_purchase?utm_source=portal&utm_medium=cdb&utm_campaign=firstpurchase&utm_term=0110
浏览器信息
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36
请描述您的问题
标题:腾讯云云产品新购特惠,五折上云!
地址:https://cloud.tencent.com/act/first_purchase?utm_source=portal&utm_medium=cdb&utm_campaign=firstpurchase&utm_term=0110
浏览器信息
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:58.0) Gecko/20100101 Firefox/58.0
请描述您的问题
标题:年底大酬宾-腾讯云
地址:https://cloud.tencent.com/act/bargin?fromSource=gwzcw.634234.634234.634234
浏览器信息
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36
SELECT month(dateofappointment), COUNT(*) 'NumberOfAppointments'
FROM appointment
WHERE YEAR(dateofappointment) = '2016'
GROUP BY MONTH(dateofappointment)
这显示了我所有的月份,但是十二月不在那里,因为那一年没有预约。我如何显示十二月是0?