我是一个R编程的初学者。目前我正在尝试从包含X和Y坐标、站点名称的数据框中检索一些站点名称,并将它们复制到具有特定点的不同数据框中。
FD <- matrix(data =c(rep(1, 500), rep(0, 500),
rnorm(1000, mean = 550000, sd=4000),
rnorm(1000, mean = 6350000, sd=20000), rep(NA, 1000)),
ncol = 4, nrow = 1000, byrow = FALSE)
colnames(FD) <- c('Survival', 'X', 'Y', 'Site')
FD <- as.data.frame(FD)
shpxt <- matrix(c(526654.7,526810.5 ,6309098,6309187,530405.4,530692,
6337699, 6338056,580432.7, 580541.9, 6380246,6380391,
585761.3, 585847.6, 6379665, 6379759, 584192.1, 584279.4,
6382358, 6382710, 583421.2, 583492.4, 6379356, 6379425,
532395.5, 532515.3 , 6336421, 6336587, 534694.6, 534791.2,
6335620, 6335740, 536749.8, 536957.5, 6337584, 6338130, 590049.6,
590419.4, 6372232, 6372432, 580443, 580756.5, 6386342, 6386473,
575263.9, 575413.7, 6380416, 6380530, 584625.1, 584753.9, 6381009,
6381335), ncol = 4, nrow = 13, byrow = TRUE)
sites <- c("Brandbaeltet", "Brusaa", "Granly", "Jerup Strand", "Knasborgvej",
"Milrimvej", "Overklitten", "Oversigtsareal", "Sandmosen",
"Strandby", "Troldkaer", "Vaagholt", "Videsletengen")
colnames(shpxt) <- c("Xmin", "Xmax", "Ymin", "Ymax")
shpxt <- as.data.frame(shpxt)
shpxt["Sites"] <- sites
我的方法是使用类似于这样的嵌套for循环:
tester <- function(FD, shpxt)
{ for (i in 1:nrow(FD)) for (j in 1:nrow(shpxt)) # Open Function
{ if (FD[i,2] >= shpxt[j,1] | FD[i,2] <= shpxt[j,2] & # Open Loop
FD[i,3] >= shpxt[j,3] | FD[i,3] <= shpxt[j,4])
{ # Open Consequent
FD[i,4]=shpxt[j,5]
{break}
} else # Close Consequent
{FD[i,4] <- NA # Open alternative
} # Close alternative
} # Close loop
} # Close function
tester(FD, shpxt)
本质上,我想要查找在FD中X和Y坐标落入范围内的站点,并将站点名称复制到第i行的FD$Site中。 当我在真实数据上运行循环时,我会收到以下错误消息:
test(FD, shpxt)
Error in if (FD[i, 2] >= shpxt[j, 1] | FD[i, 2] <= shpxt[j, 2] & FD[i, :
missing value where TRUE/FALSE needed
我应该如何让循环从这里开始并将所需的站点名称复制到我的FD中?
祝好,Thøger。