KU99 questions

KU99 answers

• Count occurrences of factors across multiple columns in grouped dataframe
• Passing data-variables to R formulas
• Turning vectors of strings in a dataframe into categorical variables in R
• How to test if object has "as.matrix" method?
• Estimating area curve between two curves
• how to find identical string in various columns of a data frame
• Grouped rolling average
• Extract every combination of numeric values once they reach a target sum
• Find roots of the equation in R
• How to create a matrix with four 1's in each row staggered