rle-like function that catches “run” of adjacent integers

by

1) Calculate values and then lengths based on values

s <- split(x, cumsum(c(0, diff(x) != 1)))
run.info <- list(lengths = unname(sapply(s, length)), values = unname(s))

Running it using x from the question gives this:

> str(run.info)
List of 2
 $ lengths: int [1:5] 3 6 1 2 6
 $ values :List of 5
  ..$ : num [1:3] 3 4 5
  ..$ : num [1:6] 10 11 12 13 14 15
  ..$ : num 17
  ..$ : num [1:2] 22 23
  ..$ : num [1:6] 35 36 37 38 39 40

2) Calculate lengths and then values based on lengths

Here is a second solution based on Gregor’s length calculation:

lens <- rle(x - seq_along(x))$lengths 
list(lengths = lens, values = unname(split(x, rep(seq_along(lens), lens))))

3) Calculate lengths and values without using other

This one seems inefficient since it calculates each of lengths and values from scratch and it also seems somewhat overly complex but it does manage to get it all down to a single statement so I thought I would add it as well. Its basically just a mix of the prior two solutions marked 1) and 2) above. Nothing really new relative to those two.

list(lengths = rle(x - seq_along(x))$lengths,
           values = unname(split(x, cumsum(c(0, diff(x) != 1)))))

EDIT: Added second solution.

EDIT: Added third solution.  

More Related Contents:

  1. Finding ALL duplicate rows, including “elements with smaller subscripts”
  2. Position geom_text on dodged barplot
  3. How to assign from a function which returns more than one value?
  4. Converting year and month (“yyyy-mm” format) to a date?
  5. Save multiple ggplots using a for loop
  6. Plotting contours on an irregular grid
  7. How to merge color, line style and shape legends in ggplot
  8. Horizontal/Vertical Line in plotly
  9. Usage of `…` (three-dots or dot-dot-dot) in functions [duplicate]
  10. Compute mean and standard deviation by group for multiple variables in a data.frame
  11. Subset a matrix according to a columns vector
  12. Saving multiple outputs of foreach dopar loop
  13. Fill and border colour in geom_point (scale_colour_manual) in ggplot
  14. R ggplot2 merge with shapefile and csv data to fill polygons
  15. lambda-like functions in R?
  16. Colour points in a plot differently depending on a vector of values
  17. How to tell CRAN to install package dependencies automatically?
  18. Strategies for reading in CSV files in pieces?
  19. controlling order of facet_grid/facet_wrap in ggplot2? [duplicate]
  20. How to subtract years?
  21. Set the plot title to wrap around and shrink the text to fit the plot
  22. Converting unit abbreviations to numbers
  23. Using column names as function arguments
  24. How to update a package in R?
  25. R: eval(parse(…)) is often suboptimal
  26. Is there a way to paste together the elements of a vector in R without using a loop?
  27. ddply for sum by group in R
  28. Difference between `names(df[1])
  29. Cut() error – ‘breaks’ are not unique
  30. How to use superscript in axis labels with ggplot2

Leave a Comment