In stephlocke/Rtraining: Training Materials on R

Step 5: Summarise data

OK, let's produce some tables!

• Lots of functionality, but kept quite simple here
• Read data.table intro for a great in-depth introduction

---

Basic summary

OrderTerritory[  , #Nothing in 1st position
               .( Value  = sum(TotalDue) ,
                  Volume = .N ), # Aggregations
               by = Name # Group by, no alias
               ]

---

Basic summary

knitr::kable(OrderTerritory[  , #Nothing in 1st position
               .( Value  = sum(TotalDue) ,
                  Volume = .N ), # Aggregations
               by = Name # Group by, no alias
               ]
        )

---

Top 5 sales ever

OrderTerritory[order(-TotalDue)[1:5],
               # Picks first 5 rows of TotalDue desc
               .( SalesOrderNumber, # multi-select
                  AccountNumber,
                  Region=Name, # Aliasing colum
                  TotalDue,
                  OrderDate
                  )
               ]

---

Top 5 sales ever

knitr::kable(OrderTerritory[order(-TotalDue)[1:5],
               # Picks first 5 rows of TotalDue desc
               .( SalesOrderNumber, # multi-select
                  AccountNumber,
                  Region=Name, # Aliasing colum
                  TotalDue,
                  OrderDate
                  )
               ]
        )

---

Top sale ever for each region

OrderTerritory[  ,
               .SD[which.max(TotalDue),
               # .SD is subset of rows within group

               # which.max() returns row 
               # no of largest val
                   .( SalesOrderNumber,
                      AccountNumber,
                      TotalDue,
                      OrderDate
                    )
                   ],
               by=.(Region=Name)
               #Aliasing in groupung
               ]

---

Top sale ever for each region

knitr::kable(OrderTerritory[  ,
               .SD[which.max(TotalDue),
                   .( SalesOrderNumber,
                      AccountNumber,
                      TotalDue,
                      OrderDate
                    )
                   ],
               by=.(Region=Name)
               ]
        )

stephlocke/Rtraining documentation built on May 30, 2019, 3:36 p.m.