rollfun-ans-validation.txt

# data.table dplyr
ans[(w-2):(w+2)]
tail(ans, 3)

# duckdb
dbGetQuery(con, "SELECT * FROM ans WHERE ROWID BETWEEN 1000-2-1 AND 1000+2-1")
dbGetQuery(con, "SELECT * FROM ans WHERE ROWID > (SELECT count(*) FROM ans) - 4")

# pandas
ans.head(w+2).tail(5)
ans.tail(3)

# spark
ans.head(w+2)[-5:]
ans.tail(3)

# q6
data.table::as.data.table(ans)[(w-52):(w-48)]
data.table::as.data.table(ans)[(w+48):(w+52)]
tail(data.table::as.data.table(ans), 3)

dbGetQuery(con, "SELECT * FROM ans WHERE ROWID BETWEEN 1000-50-2-1 AND 1000-50+2-1")
dbGetQuery(con, "SELECT * FROM ans WHERE ROWID BETWEEN 1000+50-2-1 AND 1000+50+2-1")
dbGetQuery(con, "SELECT * FROM ans WHERE ROWID > (SELECT count(*) FROM ans) - 4")

ans.head(w-50+2).tail(5)
ans.head(w+50+2).tail(5)
ans.tail(3)

ans.head(w-50+2)[-5:]
ans.head(w+50+2)[-5:]
ans.tail(3)

# q8
ans[900:904]
tail(ans, 3)

dbGetQuery(con, "SELECT * FROM ans WHERE ROWID BETWEEN 900-1 AND 904-1")
dbGetQuery(con, "SELECT * FROM ans WHERE ROWID > (SELECT count(*) FROM ans) - 4")

ans.head(904).tail(5)
ans.tail(3)

ans.head(904)[-5:]
ans.tail(3)

# q9
ans[493:497]
tail(ans, 3)

dbGetQuery(con, "SELECT * FROM ans WHERE ROWID BETWEEN 493-1 AND 497-1")
dbGetQuery(con, "SELECT * FROM ans WHERE ROWID > (SELECT count(*) FROM ans) - 4")

ans.head(497).tail(5)
ans.tail(3)

# spark
ans.head(497)[-5:]
ans.tail(3)