我有数百个 Landsat8 场景,每个场景有 12 个波段。我已将它们全部存储在一个文件夹中。现在我尝试在 R 中将它们全部堆叠在一起,以便更轻松地批量处理索引。这是我使用的代码:
#Create List of files (whole path is used)
L8files = list.files(path =
"C:/Users/Felix/Desktop/Bachelorarbeit/Daten/R_Test/Only_TIF",
full.names=TRUE)
#Write Names of Files in List
getprefix = function(string){
substr(string, 61, 113)
}
L8list = lapply(L8files, getprefix)
#Defining function to stack
stack_raster= function(file){
setwd("C:/Users/Felix/Desktop/Bachelorarbeit/Daten/R_Test/Only_TIF")
prefix = substr(file, 1, 106)
suffix = "tif"
inband1 = raster(paste (prefix, paste("B1", suffix, sep ="."), sep=""))#coastal aerosol
inband2 = raster(paste (prefix, paste("B2", suffix, sep ="."), sep="")) #blue
inband3 = raster(paste (prefix, paste("B3", suffix, sep ="."), sep="")) #green
inband4 = raster(paste (prefix, paste("B4", suffix, sep ="."), sep="")) #red
inband5 = raster(paste (prefix, paste("B5", suffix, sep ="."), sep="")) #NIR
inband6 = raster(paste (prefix, paste("B6", suffix, sep ="."), sep="")) #swir1
inband7 = raster(paste (prefix, paste("B7", suffix, sep ="."), sep="")) #swir2
inband8 = raster(paste (prefix, paste("B8", suffix, sep ="."), sep="")) #PAN
inband9 = raster(paste (prefix, paste("B9", suffix, sep ="."), sep="")) #cirrus
inband10 = raster(paste (prefix, paste("B10", suffix, sep ="."), sep="")) #TIRS1
inband11 = raster(paste (prefix, paste("B11", suffix, sep ="."), sep="")) #TIRS2
inbandQBA = raster(paste (prefix, paste("QBA", suffix, sep ="."), sep=""))#Pre-Collection Quality Assessment
#stack bands
inimage = stack(inband1, inband2, inband3, inband4, inband5, inband6,
inband7, inband8,inband9, inband10, inband11, inbandQBA)
setwd("C:/Users/Felix/Desktop/Bachelorarbeit/Daten/R_Test/stacked")
sat = substr(file, 67, 70)
date = substr(file, 84, 91)
writeRaster(inimage, filename = paste(date, sat, sep="_"),
format="GTiff", overwrite=TRUE)
}
#Loop
for (i in L8list){
stack_raster(i)
}
我认为堆栈函数不知道要使用哪个文件,但我也不知道如何更改它。下面你会看到 Debug 向我展示的内容。我无法真正从中读取任何内容,但该文件不存在。
function (x, band = 1, objecttype = "RasterLayer", native = FALSE,
silent = TRUE, offset = NULL, ncdf = FALSE, ...)
{
x <- trim(x)
if (x == "" | x == ".") {
stop("provide a valid filename")
}
start <- tolower(substr(x, 1, 3))
if (!start %in% c("htt", "ftp")) {
y <- NULL
try(y <- normalizePath(x, mustWork = TRUE), silent = TRUE)
if (!is.null(y)) {
x <- y
}
}
fileext <- toupper(extension(x))
if (fileext %in% c(".GRD", ".GRI")) {
grifile <- .setFileExtensionValues(x, "raster")
grdfile <- .setFileExtensionHeader(x, "raster")
if (file.exists(grdfile) & file.exists(grifile)) {
return(.rasterFromRasterFile(grdfile, band = band,
objecttype, ...))
}
}
if (!file.exists(x)) {
if (extension(x) == "") {
grifile <- .setFileExtensionValues(x, "raster")
grdfile <- .setFileExtensionHeader(x, "raster")
if (file.exists(grdfile) & file.exists(grifile)) {
return(.rasterFromRasterFile(grdfile, band = band,
objecttype, ...))
}
else {
}
}
}
if ((fileext %in% c(".HE5", ".NC", ".NCF", ".NC4", ".CDF",
".NCDF", ".NETCDF")) | (isTRUE(ncdf))) {
return(.rasterObjectFromCDF(x, type = objecttype, band = band,
...))
}
if (fileext == ".GRD") {
if (.isNetCDF(x)) {
return(.rasterObjectFromCDF(x, type = objecttype,
band = band, ...))
}
}
if (fileext == ".BIG" | fileext == ".BRD") {
return(.rasterFromRasterFile(x, band = band, objecttype,
driver = "big.matrix", ...))
}
if (!is.null(offset)) {
return(.rasterFromASCIIFile(x, offset, ...))
}
if (fileext %in% c(".BIN")) {
r <- .rasterFromNSIDCFile(x)
if (!is.null(r))
return(r)
}
if (!native) {
if (!.requireRgdal(FALSE)) {
native <- TRUE
}
}
if (native) {
if (fileext == ".ASC") {
return(.rasterFromASCIIFile(x, ...))
}
if (fileext %in% c(".BIL", ".BIP", ".BSQ")) {
return(.rasterFromGenericFile(x, type = objecttype,
...))
}
if (fileext %in% c(".RST", ".RDC")) {
return(.rasterFromIDRISIFile(x, ...))
}
if (fileext %in% c(".DOC", ".IMG")) {
return(.rasterFromIDRISIFile(x, old = TRUE, ...))
}
if (fileext %in% c(".SGRD", ".SDAT")) {
return(.rasterFromSAGAFile(x, ...))
}
}
if (fileext == ".DOC") {
if (file.exists(extension(x, ".img"))) {
return(.rasterFromIDRISIFile(x, old = TRUE, ...))
}
}
if (fileext %in% c(".SGRD", ".SDAT")) {
r <- .rasterFromSAGAFile(x, ...)
if (r@file@toptobottom | r@data@gain != 1) {
return(r)
}
}
if (!.requireRgdal(FALSE)) {
stop("Cannot create RasterLayer object from this file; perhaps you need
to install rgdal first")
}
test <- try(r <- .rasterFromGDAL(x, band = band, objecttype,
...), silent = silent)
if (class(test) == "try-error") {
if (!file.exists(x)) {
stop("Cannot create a RasterLayer object from this file. (file does not
exist)")
}
stop("Cannot create a RasterLayer object from this file.")
}
else {
return(r)
}
}