Mamoun Benghezal questions

Mamoun Benghezal answers

• How to add horizontal line to xy plot in lattice
• filter R data frame with one column - keep data frame format [duplicate]
• ggplot2: add line for sum of group values at each x
• Determine index of elements in a vector which occur only once
• Avoiding multiple for-loops in R to calculate a matrix
• Calculating an average in a data frame based on locations from separate columns
• How do I sum the values of columns in several tables if tables have different lengths?
• R fastest way to get values from list as vector [duplicate]
• Insert an empty column between every column of a dataframe in R
• use dplyr to select columns