In pvrqualitasag/PedigreeFromTvdData: Import pedigree data from TVD-Input files

This notebook shows some scratch ideas and experiments with dplyr and the verbs to change certain values within a variable

A simple example using case_when

We get started with a few examples from ?dplyr::case_when

require(dplyr)
x <- 1:50
case_when(
  x %% 35 == 0 ~ "fizz buzz",
  x %% 5 == 0 ~ "fizz",
  x %% 7 == 0 ~ "buzz",
  TRUE ~ as.character(x)
)

Doing the same thing with a replacement closer to our needs

x <- 1:50
case_when(
  x %% 9  == 0 ~ "NA",
  x %% 35 == 0 ~ "fizz buzz",
  x %% 5 == 0 ~ "fizz",
  x %% 7 == 0 ~ "buzz",
  TRUE ~ as.character(x)
)

Apparantly, we cannot use the "NA" without quotes. Trying with the typed version of NA

x <- 1:50
case_when(
  x %% 9  == 0 ~ NA_character_,
  x %% 35 == 0 ~ "fizz buzz",
  x %% 5 == 0 ~ "fizz",
  x %% 7 == 0 ~ "buzz" ,
  TRUE ~ as.character(x)
)

Usage and Arguments

s_dpcw <- "`dplyr::case_when`"
s_dpcw_hf <- paste0("?", s_dpcw) 

From the sections Usage and Arguments in the help file of r s_dpcw_hf, we can see that r s_dpcw can take any number of arguments which is denoted by the three dots. The arguments must be a sequence of two sided formulas. A two-sided formula consists of a LHS and a RHS which are separated by a tilde (~). For the purpose of the arguments in r s_dpcw

Vector function

We are looking at the section Vector Functions in a RStudio blog post. The second function in the section on Vector Functions is called na_if(). The example used in the blog post is as follows

x <- c(1, 5, 2, -99, -99, 10)
na_if(x, -99)

The function na_if() is certainly useful when we want to replace a single value by NA. But we want to use it for a vector of values leading to

na_if(x, c(1,2))

But the above produces an error. Hence we are searching for a different function. One possible candidate is if_else(). The example given in the blog post is

x <- factor(sample(letters[1:5], 10, replace = TRUE))
if_else(x %in% c("a", "b", "c"), x, factor(NA))

Here an intersting side note is the difference to ifelse() in R-base

ifelse(x %in% c("a", "b", "c"), x, factor(NA))

In the version of R-base, the components of x are replaced by the levels and are no longer of type factor.

pvrqualitasag/PedigreeFromTvdData documentation built on May 29, 2019, 7:50 a.m.