Question

我在stackexchange上看到了其他这样的例子，但似乎无法使它们适应我的代码。

问题：我有一个.rds文件的文件夹，我想读入R，然后将所有文件堆叠在一起，所以我可以采取均值和标准差。所有的.rds文件都是正式的RasterLayer＆＃39;当被带入R时，如果那是相关的。

示例代码：

 # file path to folder where .rds files are stored
   path = "~/Predictions/"
   # create place to store files
   stack <-""
   # create vector of all .rds files in folder
   pred.dates <- dir(path, pattern =".rds")
   # loop to bring in each .rds file
   for(i in 1:length(pred.dates)){
   file <- readRDS(file.names[i],".rds")
   stack <- rbind(stack, file)
   }

   # take mean of all .rds files stacked together and plot 
   pred_mean <- mean(stack, na.rm=T)
   plot(pred_mean)

   # take sd of all .rds files stacked together and plot 
   pred_sd <- sd(stack, na.rm = T)
   plot(pred_sd)

但是，它会返回错误：

Error in gzfile(file, "rb") : cannot open the connection
In addition: Warning message:
In gzfile(file, "rb") :
  cannot open compressed file 'Pred_.rds', probable reason 'No such file or directory'

似乎这应该是直截了当的，但也许我没有使用正确的功能。谢谢！

Answer 1

你可以这样做：

shutil.copyfileobj(fr,fw,length = 1000000)  # read by 1MB chunks

Answer 2

我认为F.Privé解决方案的问题在于他们使用rbind代替stack。我建议你做

library(raster)
files <- list.files(path = path, pattern = "\\.rds$", full.names = TRUE)
r <- lapply(files, readRDS)
s <- stack(r)

读取多个.rds文件并创建一个对象

2 个答案: