Reshaping: Long to Wide

• dcast(){reshape2}

install.packages("reshape2")
library(reshape2)

• Syntax of dcast()

id variables ~ variable variables

ideDataFrame <- dcast(longDataFrame, idVariableColumn1 + idVariableColumn2 ~ variableColumn, value.var="Nameolumn with the measurement values")

• [S]pecify the formula where

  • ID variables
    • The variables you want repeating in each row
    • those that remain in columns
    • are before the tilde (~)
  • variable variables
    • Those that should become column headers
    • those that get 'moved to the top'
    • are after the tilde (~)
  • The third argument for dcast() -assigns the name of the column that holds your measurement values to value.var.

• Code of dcast()

companiesWide <- dcast(companiesLong, fy + company ~ financialCategory, value.var="amount")

Reference:

• 4 data wrangling tasks in R for advanced beginners | Computerworld