我正在尝试将BEV和PHEV的全球销售数据调整为逻辑增长函数。
例如，我正在使用R-code for Logistic Growth Model of Australian Population in R (by Elise Gould)
但是用这种方法我得到了错误：
qr.default（.swts * gr）中的错误： 外部函数调用中的NA / NaN / Inf（arg 1） 另外：警告消息： 在Ops.factor（xmid，input）中：“-”对因子没有意义
我的数据是：
EV_temp<-structure(list(Country = structure(c(21L, 21L, 21L, 21L, 21L,
21L, 21L, 21L, 21L, 21L, 21L, 21L, 21L), .Label = c("Australia",
"Brazil", "Canada", "Chile", "China", "Finland", "France", "Germany",
"India", "Japan", "Korea", "Mexico", "Netherlands", "New Zealand",
"Norway", "Others", "Portugal", "South Africa", "Sweden", "Thailand",
"Total", "United Kingdom", "United States"), class = "factor"),
Year = structure(1:13, .Label = c("2005", "2006", "2007",
"2008", "2009", "2010", "2011", "2012", "2013", "2014", "2015",
"2016", "2017"), class = "factor"), TotalSales = c(1.89,
2.23, 2.69, 5.15, 7.48, 14.26, 61.33, 179.03, 381.3, 703.65,
1239.45, 1982.04, 3109.05)), class = "data.frame", row.names = c(NA,
-13L), .Names = c("Country", "Year", "TotalSales"))
代码：
EV.ss <- nls(TotalSales ~ SSlogis(Year, phi1, phi2, phi3), data = EV_temp)
如果有人可以指出正确的方向来解决这个问题，将不胜感激。