[R] data.frame and ddply

[arnaud Gaboury]

Dear group,

Here is my df :


futures <-
structure(list(CONTRAT = c("WHEAT May/10 ", "WHEAT May/10 ", 
"WHEAT May/10 ", "WHEAT May/10 ", "COTTON NO.2 May/10 ", "COTTON NO.2 May/10
", 
"COTTON NO.2 May/10 ", "PLATINUM Jul/10 ", " SUGAR NO.11 May/10 ", 
" SUGAR NO.11 May/10 ", " SUGAR NO.11 May/10 ", " SUGAR NO.11 May/10 ", 
" SUGAR NO.11 May/10 ", "ROBUSTA COFFEE (10) May/10 ", "ROBUSTA COFFEE (10)
May/10 ", 
"ROBUSTA COFFEE (10) May/10 ", "ROBUSTA COFFEE (10) May/10 ", 
"ROBUSTA COFFEE (10) May/10 ", "ROBUSTA COFFEE (10) May/10 ", 
"ROBUSTA COFFEE (10) May/10 ", "ROBUSTA COFFEE (10) May/10 ", 
"ROBUSTA COFFEE (10) May/10 ", "ROBUSTA COFFEE (10) May/10 ", 
"ROBUSTA COFFEE (10) May/10 ", "ROBUSTA COFFEE (10) May/10 "), 
    QUANTITY = c(1, 1, 1, 1, 1, 1, 1, -1, 1, 1, 1, 1, 1, 2, 1, 
    1, 1, 2, 1, 1, 1, 1, 2, 1, 1), SETTLEMENT = c("467.7500", 
    "467.7500", "467.7500", "467.7500", "78.1300", "78.1300", 
    "78.1300", "1,739.4000", "16.5400", "16.5400", "16.5400", 
    "16.5400", "16.5400", "1,353.0000", "1,353.0000", "1,353.0000", 
    "1,353.0000", "1,353.0000", "1,353.0000", "1,353.0000", "1,353.0000", 
    "1,353.0000", "1,353.0000", "1,353.0000", "1,353.0000")), .Names =
c("CONTRAT", 
"QUANTITY", "SETTLEMENT"), row.names = c(NA, 25L), class = "data.frame")

Here is my code :

>opfut=ddply(futures, c("CONTRAT","SETTLEMENT"), summarise, POSITION=
sum(QUANTITY))

Here is the output:

> opfut
                      CONTRAT SETTLEMENT POSITION
1         SUGAR NO.11 May/10     16.5400        5
2         COTTON NO.2 May/10     78.1300        3
3            PLATINUM Jul/10  1,739.4000       -1
4 ROBUSTA COFFEE (10) May/10  1,353.0000       15
5               WHEAT May/10    467.7500        4

It is almost exactly what I want, except I am expecting the POSITION column
before the SETTLEMENT column. How can I modified my code to obtain this?

TY



***************************
Arnaud Gaboury
Mobile: +41 79 392 79 56
BBM: 255B488F