我有一个for循环，可以返回4个不同的答案，这是正确的，但是当我尝试将这些值检索到data.frame时，我得到“ [<-.data.frame（*tmp*，p中的错误，1，value = 29.1520685791182）：   数据帧的下标分配中不允许缺少值”

目标：我试图获取在data.frame中分别打印29、485，-14、12的值

library("xts")
library("quantmod")
library("fredr")


Tesla <- getSymbols("TSLA",from=as.Date("2014-11-03"),to=as.Date("2019-11-03"))
Amazon <- getSymbols("AMZN",to=as.Date("2019-11-03"))
Equinor <- getSymbols("EQNR",from="2014-11-03",to="2019-11-03")
FTSE100 <- getSymbols("^FTSE",to="2019-11-03")

dftest <- data.frame(merge(TSLA$TSLA.Close,AMZN$AMZN.Close,EQNR$EQNR.Close,FTSE$FTSE.Close))

df <- data.frame(matrix(nrow = 1,ncol = 4)) #The data.frame where i want my returned values from print(pros) to be in.
colnames(dfProsent) <- c("TESLA","AMAZON","EQUINOR","FTSE")

for (p in dftest) {
  pros <- ((last(as.numeric(p)))-(first(as.numeric(p))))/(first(as.numeric(p)))*100
  print(pros) #this print out 29,485,-14,12
df[p,1] <- pros #the problem
}