有些难以理解。我目前有一个netcdf文件,其中包含1979-2016年每月气候平均值。我想从这个大文件中制作出单独的年栅格堆叠(即从1个栅格堆叠变成38个)。我无法找到解决方法。任何建议都将是极好的!可以在此处找到数据:http://nimbus.cos.uidaho.edu/abatz/DATA/vpd19792016.nc
我已经开始了以下工作:
library(raster)
library(lubridate)
library(rgdal)
library(tidyverse)
library(tools)
file = "../data/raw/climate/aet_19792016.nc"
file_split <- file %>%
basename %>%
strsplit(split = "_") %>%
unlist
var <- file_split[1]
year <- substr(file_split[2], start = 1, stop = 4)
endyear <- substr(file_split[2], start = 5, stop = 8)
start_date <- as.Date(paste(year, "01", "01", sep = "-"))
end_date <- as.Date(paste(ifelse(year == endyear, year, endyear), "12", "31", sep = "-"))
date_seq <- seq(start_date, end_date, by = "1 month")
month_seq <- month(date_seq)
nc <- nc_open(file)
nc_att <- attributes(nc$var)$names
ncvar <- ncvar_get(nc, nc_att)
tvar <- aperm(ncvar, c(3,2,1))
proj <- "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0 "
raster <- brick(tvar, crs= proj)
extent(raster) <- c(-124.793, -67.043, 25.04186, 49.41686)
names(raster) <- paste(var, year(date_seq),
unique(month(date_seq, label = TRUE)),
sep = "_")
unstack(raster)
提前感谢任何建议!