akrun questions

akrun answers

• Extract elements from a vector using a sparse matrix in R without converting to dense matrix
• Conditional replacement of a comma with a dot in a numeric column
• How to filter a dataframe by rows without losing the index (or row number)?
• R group_by with ranges (or aggregate)
• How to drop duplicate rows based on another column condition?
• How to create multiple columns from combination of pairs of another column?
• R - Extract words with a pattern and replace them with the words in inverse order
• Distinct sequence pattern with counts
• Create new column when when values repeat 3 or more times
• R select from data frame: by date with repeated factors