The order function describes how it reads in its lists
?order
...
a sequence of numeric, complex, character or logical vectors, all of the same length, or a classed R object.
-----------------------------------------------------
> order
function (..., na.last = TRUE, decreasing = FALSE, method = c("auto",
"shell", "radix"))
{
z <- list(...)
decreasing <- as.logical(decreasing)
if (length(z) == 1L && is.numeric(x <- z[[1L]]) && !is.object(x) &&
length(x) > 0) {
if (.Internal(sorted_fpass(x, decreasing, na.last)))
return(seq_along(x))
}
Most people use order in a hacked, non-variadic form:
myData.sorted = myData[ order(-myData[,date.idx],-myData[,(1+date.idx)]), ];
I have written a function to make this form variadic:
#########################################
## how I want it, doesn't work
#fdf = sdf[order(vecs), ];
#########################################
## non-variadic approach, does work
fdf = sdf[order( vecs[,1],vecs[,2],vecs[,3] ), ];
So I have a matrix that I want to decompose based on its variadic number of columns, yet cast that matrix as a sequence of vectors that the order function can handle. unlist? maybe as.list?
How can I cast a matrix to be a sequence of vectors based on its number of columns?
convertDateStringToFormat = function (strvec,format.out="%Y",format.in="%Y-%m-%d %H:%M:%S",numeric=TRUE)
{
p.obj = strptime(strvec, format=format.in);
o.obj = strftime(p.obj, format=format.out);
if(numeric) { as.numeric(o.obj); } else { o.obj; }
}
library(datasets);
data(iris);
df = iris[1:10,];
df$date.strings = c("3/24/2010 18:33", "9/3/2009 17:28", "10/14/2009 11:40", "7/3/2015 11:16","11/18/2010 1:29","4/23/2011 0:08","10/6/2010 11:13","7/26/2009 13:23","4/9/2008 13:40","8/20/2008 11:32");
df$year = convertDateStringToFormat(df$date.strings,"%Y","%m/%d/%Y %H:%M");
df$week = convertDateStringToFormat(df$date.strings,"%W","%m/%d/%Y %H:%M");
df$day = convertDateStringToFormat(df$date.strings,"%j","%m/%d/%Y %H:%M");
df$date.strings = NULL;
> df
Sepal.Length Sepal.Width Petal.Length Petal.Width Species year week day
1 5.1 3.5 1.4 0.2 setosa 2010 12 83
2 4.9 3.0 1.4 0.2 setosa 2009 35 246
3 4.7 3.2 1.3 0.2 setosa 2009 41 287
4 4.6 3.1 1.5 0.2 setosa 2015 26 184
5 5.0 3.6 1.4 0.2 setosa 2010 46 322
6 5.4 3.9 1.7 0.4 setosa 2011 16 113
7 4.6 3.4 1.4 0.3 setosa 2010 40 279
8 5.0 3.4 1.5 0.2 setosa 2009 29 207
9 4.4 2.9 1.4 0.2 setosa 2008 14 100
10 4.9 3.1 1.5 0.1 setosa 2008 33 233
>
There is a ... step here, but we get a matrix vecs that looks like this:
vecs = matrix(
c(2010,2009,2009,2015,2010,2011,2010,2009,2008,2008,
-12,-35,-41,-26,-46,-16,-40,-29,-14,-33,
83,246,287,184,322,113,279,207,100,233),
nrow=10,ncol=3,byrow=F);
> vecs
[,1] [,2] [,3]
[1,] 2010 -12 83
[2,] 2009 -35 246
[3,] 2009 -41 287
[4,] 2015 -26 184
[5,] 2010 -46 322
[6,] 2011 -16 113
[7,] 2010 -40 279
[8,] 2009 -29 207
[9,] 2008 -14 100
[10,] 2008 -33 233
>
So I try this: vec2 = as.data.frame(vecs); class(vec2) = "list"; based on another post (alfymbohm) How to convert a matrix to a list of column-vectors in R?
Currently, this works:
df[order( vecs[,1],vecs[,2],vecs[,3] ), ];
Sepal.Length Sepal.Width Petal.Length Petal.Width Species year week day
10 4.9 3.1 1.5 0.1 setosa 2008 33 233
9 4.4 2.9 1.4 0.2 setosa 2008 14 100
3 4.7 3.2 1.3 0.2 setosa 2009 41 287
2 4.9 3.0 1.4 0.2 setosa 2009 35 246
8 5.0 3.4 1.5 0.2 setosa 2009 29 207
5 5.0 3.6 1.4 0.2 setosa 2010 46 322
7 4.6 3.4 1.4 0.3 setosa 2010 40 279
1 5.1 3.5 1.4 0.2 setosa 2010 12 83
6 5.4 3.9 1.7 0.4 setosa 2011 16 113
4 4.6 3.1 1.5 0.2 setosa 2015 26 184
And what I want to work fails. I use vec2 to distinguish it.
vec2 = as.data.frame(vecs); class(vec2) = "list";
df[order(vec2), ];
It (the order function) throws the following error:
Error in order(vec2) : unimplemented type 'list' in 'orderVector1'
I see your approach as the cast-as-list idea I found elsewhere.
Ideally, I would want a function such as
vec2 = castMatrixToSequenceOfLists(vecs);
where
https://stackoverflow.com/questions/6819804/how-to-convert-a-matrix-to-a-list-of-column-vectors-in-r
castMatrixToSequenceOfLists = function(mat)
{
list_length = ncol(mat);
out_list = vector("list", list_length);
for(i in 1:list_length)
{
out_list[[i]] = mat[,i]; # double brackets [[1]]
}
out_list;
}
Did not work! Throws the same error (the order function):
vec2 = castMatrixToSequenceOfLists(vecs);
df[order(vec2), ];
Error in order(vec2) : unimplemented type 'list' in 'orderVector1'
Again, variadic doesn't currently work because the matrix is not a "sequence of vectors" according to the manual for order.
How do I cast a matrix as a sequence of vectors based on its number of columns so the order function will accept it?
mat_order <- function(x) do.call(order, split(x, (seq(x) - 1) %/% nrow(x)))
> df[mat_order(vecs),]
Sepal.Length Sepal.Width Petal.Length Petal.Width Species year week day
10 4.9 3.1 1.5 0.1 setosa 2008 33 233
9 4.4 2.9 1.4 0.2 setosa 2008 14 100
3 4.7 3.2 1.3 0.2 setosa 2009 41 287
2 4.9 3.0 1.4 0.2 setosa 2009 35 246
8 5.0 3.4 1.5 0.2 setosa 2009 29 207
5 5.0 3.6 1.4 0.2 setosa 2010 46 322
7 4.6 3.4 1.4 0.3 setosa 2010 40 279
1 5.1 3.5 1.4 0.2 setosa 2010 12 83
6 5.4 3.9 1.7 0.4 setosa 2011 16 113
4 4.6 3.1 1.5 0.2 setosa 2015 26 184
This works as expected in variadic form.
If you want to pass the columns of a matrix to order as if you were calling order(mat[,1], mat[,2], mat[,3]) etc, then this one line function achieves that:
mat_order <- function(x) do.call(order, split(x, (seq(x) - 1) %/% nrow(x)))
It first splits the matrix columns into a list of vectors using a little modular maths, then uses do.call(order, ...) on the result, which has the effect of passing each list element (i.e. each vector) as variadics.