jblood94 questions

jblood94 answers

• Append first row by group to original data
• How can I efficiently vectorize the integrate function in R?
• Find columns that are constant by groups
• Rolling join with multiple matches
• How can I vectorize the loop in this sapply call?
• Efficiently reconstruct state variable from event times in R
• How to perform a conditional join on statement containing both AND and OR operators?
• fcase to multiple outputs
• Fast subset based on list of ids
• Why is my implementation of rgeom faster than R's?