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

This document shows certain experiments with finding unique columns in a tbl_df using dplyr. The material is copied from https://stackoverflow.com/questions/22959635/remove-duplicated-rows-using-dplyr.

We start by generating a random dataframe samples from a given distribution.

suppressPackageStartupMessages(library(dplyr))
set.seed(123)
df <- data.frame(
  x = sample(0:1, 10, replace = T),
  y = sample(0:1, 10, replace = T),
  z = 1:10
)
df

Then we just want to keep the rows with unique entries over the columns x and y.

(df %>% distinct(x, y))

As shown in the result, just columns x and y are kept. With the additional option .keep_all = TRUE, we get a different behavior.

(df %>% distinct(x, y, .keep_all = TRUE))

We try to find which combinations of the grouping variables x and y occur how many times.

(df %>% group_by(x, y) %>% summarise(n = n()))

In case, we just want to find those which occur more than once, i.e., which are not unique, we filter on $n$.

(df %>% group_by(x, y) %>% summarise(n = n()) %>% filter(n > 1))

Another question is whether the whole thing also works with indices instead of names.

(df %>% group_by(.[[1]], .[[2]]) %>% summarise(n = n()) %>% filter(n > 1))

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