R语言 处理PBDB数据之 用自编函数结合for循环来进行 纬度分带

latzone <- function(stg, lat1, lat2){ 

wq <- get(paste("TS", stg ,sep = ""))

results <- if(lat1 == -15 & lat2 == 15){
subset(wq, paleolat > lat1 & paleolat < lat2)
}else{
rbind(subset(wq, paleolat > lat1 & paleolat < lat2),
subset(wq, paleolat > -lat2 & paleolat < -lat1))

}
return(results)
}

for (i in 17:24) {
for (lat1 in c(-15,15,30,45)) {
for (lat2 in c(15,30,45,90)) {
if (lat2-lat1 == 30 | lat2-lat1==15 | lat2-lat1==45){
assign(paste("pltd", i, lat1, lat2, sep = ""),latzone(stg = i, lat1, lat2))
}
}
}
}

rm('pltd17-1530','pltd171545','pltd18-1530','pltd181545','pltd19-1530','pltd191545','pltd20-1530',
'pltd201545','pltd21-1530','pltd211545','pltd22-1530','pltd221545','pltd23-1530',
'pltd231545','pltd24-1530','pltd241545')