README.md

In fangfeiliu/recurpkg: Calculating a recursive sequence vector and possible dataset for plot

recurpkg

The goal of recurpkg is to calculate a sequence vector defined as following: (X_n) = (X_{n-1}) +|(X_{n-2} - X_{n-3)}|/2

That is, element n is the sum of element n−1 and the absolute value of the difference between elements n−2 and n−3 divided by two where each element is a number. For example, if we let (X_1)=3, (X_2)=1, and (X_3)=10, then (X_4) is (X_4) = 10+ |1−3|/2 =11.

If the input is a vector, then the initial three numeric values will be taken as initial values. If the input is a dataframe, then the dataframe should has 4 columns, while the first three columns are the initial values of the sequence and the last columns will be the nth element of the sequence. The output will be a plot with x axis as the sequence position n, y axis as the sequence value.

Installation

"This package is only available by permission of the author at

install.packages(“https://github.com/fangfeiliu/recurpkg.git”)

install.packages("recurpkg")

Example

This is a basic example which shows you how to solve a common problem:

library(recurpkg)
## basic example code
## vector calculation
## vector length is equal to three
recur_vec(x = c(2, 4, 3), n = 3)
#> [1] 3

## vector length is greater than 3
recur_vec(x = c(2, 4,3,4), n = 3)
#> [1] 3

## vector length is equal to three and the sequence number is greater than 3
recur_vec(x = c(2, 4, 3), n = 5)
#> [1] 4.5

## sequence number is not an integar
recur_vec(x = c(2, 4, 3), n = 4.5)
#> [1] "the sequence number indicator must be an integer"

## vector contains both numeric and character values
recur_vec(x = c(2,'a',4,'b', 3), n = 4)
#> [1] 4

#dataset example
my_data <- tibble::tribble(
  ~x, ~y, ~z, ~n,
  2,4,3,3,
  2,4,3,5,
  2,4,3,7,
  2,4,3,10,
  2,4,3,15,
  2,4,3,20,
  2,4,3,25
)

recur_dataset(my_data)

fangfeiliu/recurpkg documentation built on Aug. 2, 2020, 1:50 a.m.