函数输出到data.frame

Question

I have two functions:

c <- function(i, n=2009, t=2000){
  vect1 <- vector('numeric', length(t:n))
  w <- n-t
  for(q in 0:w){
    a <- 1/((1+i)^(q+1))
    b <- q+t
    vect1[q+1] <- a
  }
  return(vect1)
}

and

p <- function(i, n=2009, t=2000){
  w <- n-t
  for(q in 0:w){
    a <- c(i, n, q+t)
    print(a)
  } 
}

Upon defining both functions and running p(0.10), a table similar to the following is obtained, but it is printed. I need the output in a data.frame so that I can join it with other data.

0.909090909 0   0   0   0   0   0   0   0   0
0.826446281 0.909090909 0   0   0   0   0   0   0   0
0.751314801 0.826446281 0.909090909 0   0   0   0   0   0   0
0.683013455 0.751314801 0.826446281 0.909090909 0   0   0   0   0   0
0.620921323 0.683013455 0.751314801 0.826446281 0.909090909 0   0   0   0   0
0.56447393  0.620921323 0.683013455 0.751314801 0.826446281 0.909090909 0   0   
etc.

Answer 1

You could do something like this, which gives you a one-column data frame. I'm not exactly sure what you're trying to do, or to what other data you want to join this. Maybe it will help you get to where you're trying to go:

cFunc <- function(i, n=2009, t=2000){
  vect1 <- vector('numeric', length(t:n))
  w <- n-t
  for(q in 0:w){
    a <- 1/((1+i)^(q+1))
    b <- q+t
    vect1[q+1] <- a
  }
  return(vect1)
}

p <- function(i, n=2009, t=2000){
  w <- n-t
  a1 <- list()
  for(q in 0:w){
    q <- q+1
    a1[[q]] <- cFunc(i, n, q+t)
  } 
  return(a1)
}
listp <- p(0.10)
listp <- lapply(listp, as.data.frame)
listp <- data.table::rbindlist(listp, fill = TRUE)

Result:

> head(listp)
      X[[i]]
1: 0.9090909
2: 0.8264463
3: 0.7513148
4: 0.6830135
5: 0.6209213
6: 0.5644739