如何解决匹配栅格在 foreach 循环中不起作用 我最初为堆叠对齐栅格所采取的步骤 - 仅供参考从这里开始重现错误
我正在研究涵盖整个怀俄明州的栖息地占用率预测。某些站点协变量栅格在预测中起作用,而其他具有匹配分辨率、范围等的则不起作用。
我的代码的一个可重现的简短示例如下。经过大量故障排除后,我发现我需要使用 5 个栅格中的 3 个栅格,这会导致此脚本失败,所有栅格都出现相同的错误。 我假设我的栅格以某种方式损坏(?),但想看看是否有人对可能发生的事情有其他想法。
数据位于 this link。数据是未标记的对象(另存为 .rds)和 2 个非常小的剪辑:1. 有效的栅格,以及 2. 无效的栅格之一
我最初为堆叠对齐栅格所采取的步骤 - 仅供参考
#ndvi <- raster(paste(getwd(),"./Original_rasters/ndvi_summer.TIF",sep = ""))
#precip <- raster(paste(getwd(),"./Original_rasters/bioclim15.TIF",sep = ""))
#temp <- projectExtent(original,original)
#res(temp) <- 220
#sNoJoy <- resample(ndvi,temp)
#sampleJoy <- resample(precip,temp)
从这里开始重现错误
library(raster)
library(unmarked)
sampleData <- readRDS("./sampleData.RDS")
# Formula referencing raster that does not work
fmTest <- occu(~ Day + Min_TempC + AvailTN_prop ~ ndvi.summer,sampleData)
fmTest
# Formula referencing raster that DOES work
#fmTest <- occu(~ Day + Min_TempC + AvailTN_prop ~ bc15_220,# sampleData)
# Formula for both variables that fails also
#fmTest <- occu(~ Day + Min_TempC + AvailTN_prop ~ ndvi.summer + bc15_220,# sampleData)
# Load and name rasters so formulas can find them
sampleJoy <- raster(paste(getwd(),"./sampleGoodRas.TIF",sep = ""))
names(sampleJoy) <- "bc15_220"
sNoJoy <- raster(paste(getwd(),"./sampleBadRas.TIF",sep = ""))
names(sNoJoy) <- "ndvi.summer"
compareRaster(sampleJoy,sNoJoy) # Returns "[1] TRUE"
# pm <- stack(sampleJoy)
pm <- stack(sNoJoy)
# pm <- stack(sNoJoy,sampleJoy)
###########################Combine Function#####################################
comb <- function(x,...) {
mapply("rbind",x,...,SIMPLIFY = F)
}
# This combine function allows foreach to return a list containing multiple
# matrices making it easy to insert results into raster templates
############################ Foreach Code #####################################
#Assemble cluster for parallel processing. Code works in Windows or other O/S#
ifelse(Sys.info()["sysname"] != "Windows",c(require(doMC),nc <- detectCores()-1,registerDoMC(nc)),c(require(doParallel),cl <- makeCluster(nc),registerDoParallel(cl)))
# Foreach loop returning predicted values,SE,LCI,and UCI
pred <- foreach(i = 1:nrow(pm),.combine = comb,.multicombine = T,.maxcombine = 90,.packages = c("unmarked","raster")) %dopar% {
# make raster into a data.frame row by row for prediction
tmp <- as.data.frame(pm[i,],xy = T)
# Predict the new data
pred <- predict(fmTest,"state",tmp)
# Make a list of 4 matrices to retrieve them from the loop
list(Predicted = pred$Predicted,SE = pred$SE,lower = pred$lower,upper = pred$upper)
}
# Close the cluster
stopCluster(cl)
## Using sampleJoy produces a list of 4 matrices which are easily coerced into
## raster format: Prediction,lower,and upper,as it should.
## Using sNoJoy produces:
# Error in { :
# task 1 Failed - "Matrices must have same number of rows in
# cbind2(.Call(dense_to_Csparse,x),y)"
## Rasters are the same extent,same origin,same resolution,etc.
#
### Not Working
# > pm
# class : RasterStack
# dimensions : 15,2675,40125,1 (nrow,ncol,ncell,nlayers)
# resolution : 220,220 (x,y)
# extent : 201539.7,790039.7,647050.2,650350.2 (xmin,xmax,ymin,ymax)
# crs : +proj=lcc +lat_0=41 +lon_0=-107.5 +lat_1=41 +lat_2=45 +x_0=500000 +y_0=200000 +datum=NAD83 +units=m +no_defs
# names : ndvi.summer
# min values : 0.09507491
# max values : 0.8002191
#
### Working Raster
# > pm
# class : RasterStack
# dimensions : 15,ymax)
# crs : +proj=lcc +lat_0=41 +lon_0=-107.5 +lat_1=41 +lat_2=45 +x_0=500000 +y_0=200000 +datum=NAD83 +units=m +no_defs
# names : bc15_220
# min values : 14
# max values : 66
解决方法
回答
出现错误是因为您在 sNoJoy
中有缺失。如果这些没有丢失,它会工作得很好。
问题重写
您的问题与您的并行代码无关。归结为:
fmTest <- occu(~ Day + Min_TempC + AvailTN_prop ~ ndvi.summer,sampleData)
fmTest2 <- occu(~ Day + Min_TempC + AvailTN_prop ~ bc15_220,sampleData)
pm <- stack(sNoJoy)
pm2 <- stack(sampleJoy)
tmp <- as.data.frame(pm[1,],xy = T)
tmp2 <- as.data.frame(pm2[1,xy = T)
pred <- predict(fmTest,"state",tmp) # fails
pred2 <- predict(fmTest2,tmp2) # works
基本原理
事实证明,您的坏栅格缺少值:
table(is.na(sNoJoy[]))
#FALSE TRUE
#35998 4127
如果我们人为地去除NA
中的sNoJoy
,并在NA
中随机写入1个sampleJoy
,那么状态翻转:
sNoJoy[is.na(sNoJoy[])] <- 1
sampleJoy[10] <- NA
### run same code as above
pred <- predict(fmTest,tmp) # now works
pred2 <- predict(fmTest2,tmp2) # now fails
因此,我会尝试弄清楚为什么您要从 NA
开始。
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