Question

我的代码是：

install.packages("forecast")
library(forecast)
fit<-auto.arima(pricetimeseries)
summary(fit)
pricetimeseriesarima<-arima(pricetimeseries, order=c(0,1,1))
forecast.Arima(pricetimeseriesarima), h=5, level=c(99.5))

然后

Error in forecast.Arima(pricetimeseriesarima, h = 5, level = c(99.5)) : 
could not find function "forecast.Arima"

我正确安装了包，并且库，它除了forecast.Arima无法正常工作，还有其他的预测。功能无法使用，如forecast.lm，forecast.HoltWinters等。

那么，这里的问题是什么，我怎么能解决呢，如果有人可以帮助我，那就太棒了，谢谢！

Answer 1

使用forecast()没有意义，只需使用Rob Hyndman在评论（here）的网址中所述的forecast::Arima()即可。此外，作为一般规则，您应该使用Hyndman and Athanasopoulos (2014)中所述的stats::arima()而不是set.seed(100) pricetimeseries <- rnorm(100) pricetimeseriesarima <- Arima(pricetimeseries, order=c(0,1,1)) forecast(pricetimeseriesarima, h=5, level=c(99.5))：

R中还有另一个函数arima（），它也适合ARIMA模型。但是，除非d = 0，否则它不允许常量c，并且它不返回forecast（）函数所需的所有内容。最后，它不允许将估计的模型应用于新数据（这对于检查预测准确性很有用）。因此，建议您改用Arima（）。

因此：

db.Collection.aggregate([
    {$match:{ "userid":"123"}}, // filter out what's not of interest
    {$facet: { // process two stages in parallel --> this will give us a single result document with the following two fields
        "newpage": [ // "newpage" holding the ids and sums per "newpage" field
            {$group:{"_id":"$newpage", "count":{"$sum":1}}}
        ],
        "page": [ // and "page" holding the ids and sums per "page" field
            {$group:{"_id":"$page", "count":{"$sum":1}}}
        ]
    }},
    {$project: {x:{$concatArrays:["$newpage", "$page"]}}}, // merge the two arrays into one
    {$unwind: "$x"}, // flatten the single result document into multiple ones so we do not need to $reduce but can nicely $group
    {$group: {_id: "$x._id", "count": {$sum: "$x.count"}}} // perform the final grouping/counting,
    {$sort: {count: -1}} // well, the sort according to your question
]);

Hyndman，Rob J.和George Athanasopoulos。预测：原则和实践。 OTexts，2014。

在我预测了预测包之后，我收到一个错误，说无法找到功能＆＃34; forecast.Arima＆＃34;，为什么？

1 个答案: