我正在使用R中amt
包的教程中的GPS跟踪数据。(代码也可用here可用,称为TestVignetteMovebank2018.R)
当我运行代码时,我从循环中得到一个错误:
#' Load libraries
library(knitr)
library(lubridate)
library(raster)
library(move)
library(amt)
library(ggmap)
library(tibble)
library(dplyr)
#' Create a login object for a user account at movebank.org
loginStored <- movebankLogin(username="MovebankWorkshop", password="genericuserforthisexercise")
#' Get overview information about a Movebank study. Be sure to check the citation and license terms if not using your own data.
getMovebankStudy(study="Martes pennanti LaPoint New York", login=loginStored) # see study-level info
#' Load data from a study in Movebank and create a MoveStack object. For more details and options see https://cran.r-project.org/web/packages/move/index.html.
fisher.move <- getMovebankData(study="Martes pennanti LaPoint New York", login=loginStored)
head(fisher.move)
#' Create a data frame from the MoveStack object
fisher.dat <- as(fisher.move, "data.frame")
#' ### Data cleaning
ind<-complete.cases(fisher.dat[,c("location_lat", "location_long", "timestamp")])
fisher.dat<-fisher.dat[ind==TRUE,]
#' Make timestamp a date/time variable
fisher.dat$timestamp<-as.POSIXct(fisher.dat$timestamp, format="%Y-%m-%d %H:%M:%OS", tz="UTC")
#' ## Creating a track in amt
trk <- mk_track(fisher.dat, .x=location_long, .y=location_lat, .t=timestamp, id = local_identifier,
crs = CRS("+init=epsg:4326"))
# Now it is easy to calculate day/night with either movement track
trk <- trk %>% time_of_day()
#' Now, we can transform back to geographic coordinates
trk <- transform_coords(trk, CRS("+init=epsg:32618"))
trk.class<-class(trk)
nesttrk<-trk%>%nest(-id)
trk<-trk %>% nest(-id) %>%
mutate(dir_abs = map(data, direction_abs,full_circle=TRUE, zero="N"),
dir_rel = map(data, direction_rel),
sl = map(data, step_lengths),
nsd_=map(data, nsd))%>%unnest()
trk<-trk%>%
mutate(
week=week(t_),
month = month(t_, label=TRUE),
year=year(t_),
hour = hour(t_)
)
class(trk)<-trk.class
#' ## SSF prep
(timestats<-trk %>% nest(-id) %>% mutate(sr = map(data, summarize_sampling_rate)) %>%
dplyr::select(id, sr) %>% unnest)
#' Time intervals range from every 2 to 15 minutes on average, depending
#' on the individual. Lets add on the time difference to each obs.
trk<-trk %>% group_by(id) %>% mutate(dt_ = t_ - lag(t_, default = NA))
#' THIS LOOP PRODUCES THE ERROR
ssfdat<-NULL
temptrk<-with(trk, track(x=x_, y=y_, t=t_, id=id))
uid<-unique(trk$id) # individual identifiers
luid<-length(uid) # number of unique individuals
for(i in 1:luid){
# Subset individuals & regularize track
temp<-temptrk%>% filter(id==uid[i]) %>%
track_resample(rate=minutes(round(timestats$median[i])),
tolerance=minutes(max(10,round(timestats$median[i]/5))))
# Get rid of any bursts without at least 2 points
temp<-filter_min_n_burst(temp, 2)
# burst steps
stepstemp<-steps_by_burst(temp)
# create random steps using fitted gamma and von mises distributions and append
rnd_stps <- stepstemp %>% random_steps(n = 15)
# append id
rnd_stps<-rnd_stps%>%mutate(id=uid[i])
# append new data to data from other individuals
ssfdat<-rbind(rnd_stps, ssfdat)
}
ssfdat<-as_tibble(ssfdat)
ssfdat
产生错误信息
错误:
.data
是损坏的grouped_df,"groups"
属性必须成为数据框
这似乎是对dplyr的最新更新的结果,因此
temp
对象不再是可用于后续功能的对象。您知道这个问题的解决方案吗?
谢谢
最佳答案
这应该在最新版本的amt中得到解决(截至昨天,在CRAN上,我相信Windows和Mac构建可能仍在等待中)。
关于r - 如何修复损坏的grouped_df?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/55277761/