На основании изображения ОП Reduce
работает
library(gtrendsR)
keyword <- "domestic violence"
date <- "2020-2-01 2020-04-06"
data_frame_AK_Anchorage <- gtrends(c(keyword), geo = "US-AK-743", gprop = "web", time = date)$interest_over_time
data_frame_AK_Anchorage <- dcast(data_frame_AK_Anchorage, date ~ keyword + geo, value.var = 'hits')
data_frame_AK_Fairbanks <- gtrends(c(keyword), geo = "US-AK-745", gprop = "web", time = date)$interest_over_time
data_frame_AK_Fairbanks <- dcast(data_frame_AK_Fairbanks, date ~ keyword + geo, value.var = 'hits')
out <- Reduce(function(...) merge(..., by = 'date'),
mget(ls(pattern = '^data_frame')))
head(out)
# date domestic violence_US-AK-743 domestic violence_US-AK-745
#1 2020-02-01 0 0
#2 2020-02-02 100 0
#3 2020-02-03 0 0
#4 2020-02-04 0 0
#5 2020-02-05 0 0
#6 2020-02-06 89 0