jO. questions

• Return multiple values and populate column in array like manner
• flatten nested list by averaging vectors
• Insert multiple rows in one table based on number in another table
• reshape/melt an asymmetric matrix according to a rowKey
• create binary matrix from data.frame
• match two data.frames based on multiple columns
• Regex: AttributeError: 'NoneType' object has no attribute 'groups'

jO. answers