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Muhammad Subianto

2006-Aug-28 17:20 UTC

[R] Remove empty list from list

Dear all,
I am still working with "list".
If I have an empty list how can I remove from list data.
Here is a toy example:
x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5,
4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
y <- list(c(1, -1, -1, 1, 1),c(1, 1, -1, -1, -1),c(1, 1, 1, 1, 1),c(1,
1, -1, 1, -1),c(-1, -1, -1, -1, -1))
## Thanks to Gabor Grothendieck for this trick.
## SIMPLIFY? SIMPLIFY >< simplify
xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)

point.class <-
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
pd.class <- points.diff(class.diffsame,xy.list)

nc.test <- vector("list",length(pd.class))
for (i in 1:length(pd.class)) {
     nc.test[[i]] <- pd.class[[i]]$point.diff
}
nc.test> nc.test[[1]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    2    7   12   17    1

[[3]]
     [,1] [,2] [,3] [,4] [,5]

[[4]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1

[[5]]
     [,1] [,2] [,3] [,4] [,5]
>I want to remove these:
nc.test[[3]]
nc.test[[5]]
Because my list data have more 1000 lists are there any simple way to do this?

Best, Muhammad Subianto


points.neighb <- function(p.class, list.nc, class.col) {
   ntuples <- nrow(p.class)
   instvec <- vector("list",length=ntuples)
   for (i in 1:ntuples) {
        # Thanks to Petr Pikal for this trick
        instvec[[i]]$class.diff <- (p.class[i,class.col] -
list.nc[[i]][,class.col])!=0
        instvec[[i]]$class.same <- (p.class[i,class.col] -
list.nc[[i]][,class.col])==0
   }
   instvec
}

points.diff <- function(p.class, list.nc) {
   ntuples <- length(list.nc)
   instvec <- vector("list",ntuples)
   for (i in 1:ntuples) {
        instvec[[i]]$point.diff <- list.nc[[i]][p.class[[i]]$class.diff,]
        instvec[[i]]$point.same <- list.nc[[i]][p.class[[i]]$class.same,]
   }
   instvec
}

Gabor Grothendieck

2006-Aug-28 17:29 UTC

head link

[R] Remove empty list from list

See this post from the weekend:
http://www.nabble.com/Re%3A-How-to-iteratively-extract-elements-out-of-a-list-p6002980.html



On 8/28/06, Muhammad Subianto <msubianto at gmail.com>
wrote:> Dear all,
> I am still working with "list".
> If I have an empty list how can I remove from list data.
> Here is a toy example:
> x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5,
> 4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
> y <- list(c(1, -1, -1, 1, 1),c(1, 1, -1, -1, -1),c(1, 1, 1, 1, 1),c(1,
> 1, -1, 1, -1),c(-1, -1, -1, -1, -1))
> ## Thanks to Gabor Grothendieck for this trick.
> ## SIMPLIFY? SIMPLIFY >< simplify
> xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)
>
> point.class <-
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
> class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
> pd.class <- points.diff(class.diffsame,xy.list)
>
> nc.test <- vector("list",length(pd.class))
> for (i in 1:length(pd.class)) {
>     nc.test[[i]] <- pd.class[[i]]$point.diff
> }
> nc.test
> > nc.test
> [[1]]
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    4    9   14   19    1
> [3,]    5   10   15   20    1
>
> [[2]]
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    2    7   12   17    1
>
> [[3]]
>     [,1] [,2] [,3] [,4] [,5]
>
> [[4]]
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    3    8   13   18   -1
> [2,]    5   10   15   20   -1
>
> [[5]]
>     [,1] [,2] [,3] [,4] [,5]
>
> >
> I want to remove these:
> nc.test[[3]]
> nc.test[[5]]
> Because my list data have more 1000 lists are there any simple way to do
this?
>
> Best, Muhammad Subianto
>
>
> points.neighb <- function(p.class, list.nc, class.col) {
>   ntuples <- nrow(p.class)
>   instvec <- vector("list",length=ntuples)
>   for (i in 1:ntuples) {
>        # Thanks to Petr Pikal for this trick
>        instvec[[i]]$class.diff <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])!=0
>        instvec[[i]]$class.same <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])==0
>   }
>   instvec
> }
>
> points.diff <- function(p.class, list.nc) {
>   ntuples <- length(list.nc)
>   instvec <- vector("list",ntuples)
>   for (i in 1:ntuples) {
>        instvec[[i]]$point.diff <- list.nc[[i]][p.class[[i]]$class.diff,]
>        instvec[[i]]$point.same <- list.nc[[i]][p.class[[i]]$class.same,]
>   }
>   instvec
> }
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

jim holtman

2006-Aug-28 17:29 UTC

head link

[R] Remove empty list from list

Here is a function I use a lot to do this:

delete.NULLs  <-  function(x.list){   # delele null/empty entries in a list
    x.list[unlist(lapply(x.list, length) != 0)]
}

> delete.NULLs(nc.test)[[1]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    2    7   12   17    1

[[3]]
     [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1



On 8/28/06, Muhammad Subianto <msubianto at gmail.com>
wrote:> Dear all,
> I am still working with "list".
> If I have an empty list how can I remove from list data.
> Here is a toy example:
> x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5,
> 4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
> y <- list(c(1, -1, -1, 1, 1),c(1, 1, -1, -1, -1),c(1, 1, 1, 1, 1),c(1,
> 1, -1, 1, -1),c(-1, -1, -1, -1, -1))
> ## Thanks to Gabor Grothendieck for this trick.
> ## SIMPLIFY? SIMPLIFY >< simplify
> xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)
>
> point.class <-
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
> class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
> pd.class <- points.diff(class.diffsame,xy.list)
>
> nc.test <- vector("list",length(pd.class))
> for (i in 1:length(pd.class)) {
>     nc.test[[i]] <- pd.class[[i]]$point.diff
> }
> nc.test
> > nc.test
> [[1]]
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    4    9   14   19    1
> [3,]    5   10   15   20    1
>
> [[2]]
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    2    7   12   17    1
>
> [[3]]
>     [,1] [,2] [,3] [,4] [,5]
>
> [[4]]
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    3    8   13   18   -1
> [2,]    5   10   15   20   -1
>
> [[5]]
>     [,1] [,2] [,3] [,4] [,5]
>
> >
> I want to remove these:
> nc.test[[3]]
> nc.test[[5]]
> Because my list data have more 1000 lists are there any simple way to do
this?
>
> Best, Muhammad Subianto
>
>
> points.neighb <- function(p.class, list.nc, class.col) {
>   ntuples <- nrow(p.class)
>   instvec <- vector("list",length=ntuples)
>   for (i in 1:ntuples) {
>        # Thanks to Petr Pikal for this trick
>        instvec[[i]]$class.diff <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])!=0
>        instvec[[i]]$class.same <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])==0
>   }
>   instvec
> }
>
> points.diff <- function(p.class, list.nc) {
>   ntuples <- length(list.nc)
>   instvec <- vector("list",ntuples)
>   for (i in 1:ntuples) {
>        instvec[[i]]$point.diff <- list.nc[[i]][p.class[[i]]$class.diff,]
>        instvec[[i]]$point.same <- list.nc[[i]][p.class[[i]]$class.same,]
>   }
>   instvec
> }
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?

Muhammad Subianto

2006-Aug-28 17:43 UTC

head link

[R] Remove empty list from list

On this day 28/08/2006 19:20, Muhammad Subianto wrote:> Dear all,
> I am still working with "list".
> If I have an empty list how can I remove from list data.
> Here is a toy example:
> x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5,
> 4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
> y <- list(c(1, -1, -1, 1, 1),c(1, 1, -1, -1, -1),c(1, 1, 1, 1, 1),c(1,
> 1, -1, 1, -1),c(-1, -1, -1, -1, -1))
> ## Thanks to Gabor Grothendieck for this trick.
> ## SIMPLIFY? SIMPLIFY >< simplify
> xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)
> 
> point.class <-
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
> class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
> pd.class <- points.diff(class.diffsame,xy.list)
> 
> nc.test <- vector("list",length(pd.class))
> for (i in 1:length(pd.class)) {
>      nc.test[[i]] <- pd.class[[i]]$point.diff
> }
> nc.test
>> nc.test
> [[1]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    4    9   14   19    1
> [3,]    5   10   15   20    1
> 
> [[2]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    2    7   12   17    1
> 
> [[3]]
>      [,1] [,2] [,3] [,4] [,5]
> 
> [[4]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    3    8   13   18   -1
> [2,]    5   10   15   20   -1
> 
> [[5]]
>      [,1] [,2] [,3] [,4] [,5]
> 
> I want to remove these:
> nc.test[[3]]
> nc.test[[5]]
> Because my list data have more 1000 lists are there any simple way to do
this?
> 
> Best, Muhammad Subianto
> 
> 
> points.neighb <- function(p.class, list.nc, class.col) {
>    ntuples <- nrow(p.class)
>    instvec <- vector("list",length=ntuples)
>    for (i in 1:ntuples) {
>         # Thanks to Petr Pikal for this trick
>         instvec[[i]]$class.diff <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])!=0
>         instvec[[i]]$class.same <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])==0
>    }
>    instvec
> }
> 
> points.diff <- function(p.class, list.nc) {
>    ntuples <- length(list.nc)
>    instvec <- vector("list",ntuples)
>    for (i in 1:ntuples) {
>         instvec[[i]]$point.diff <-
list.nc[[i]][p.class[[i]]$class.diff,]
>         instvec[[i]]$point.same <-
list.nc[[i]][p.class[[i]]$class.same,]
>    }
>    instvec
> }
> 
Dear
Jim Holtman and Gabor Grothendieck,
Thank you both very much for the suggestions!
These is exactly what I was looking for.

Best wishes, Muhammad Subianto


## delete null/empty entries in a list
delete.NULLs  <-  function(x.list){
     x.list[unlist(lapply(x.list, length) != 0)]
}

 > delete.NULLs  <-  function(x.list){
+     x.list[unlist(lapply(x.list, length) != 0)]
+ }
 > delete.NULLs  <-  function(x.list){
+     x.list[unlist(lapply(x.list, length) != 0)]
+ }
 >
 > delete.NULLs(nc.test)
[[1]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    2    7   12   17    1

[[3]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1

 >

Muhammad Subianto

2006-Aug-29 11:22 UTC

head link

[R] Remove empty list from list - remove only one row and make as matrix

Dear all,
After I work around, I found in my list of data with only one row which 
need to remove or make it as matrix.
Here I write again my other toy example:
x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5, 
4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
y <- list(c(1, -1, -1, 1, 1),c(1, -1, -1, -1, -1),c(1, 1, 1, 1, 1),c(1, 
1, -1, 1, -1),c(-1, -1, -1, -1, -1))
## Thanks to Gabor Grothendieck for this trick.
## SIMPLIFY? SIMPLIFY >< simplify
xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)

point.class <- 
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
pd.class <- points.diff(class.diffsame,xy.list)

nc.test <- vector("list",length(pd.class))
for (i in 1:length(pd.class)) {
      nc.test[[i]] <- pd.class[[i]]$point.diff
}
nc.test

# delete null/empty entries in a list
dff <- delete.NULLs(nc.test)
dff; str(dff)
 > dff
[[1]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
[1]  1  6 11 16  1

[[3]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1

 >

lapply(dff, nrow)
 > lapply(dff, nrow)
[[1]]
[1] 3

[[2]]
NULL

[[3]]
[1] 2

 >

#I can use
#dff[unlist(lapply(dff, nrow) == 1)] #2,3, etc

I have two questions here:
a. I need to remove dff[[2]]
b. How to make it as matrix (in list). I mean the result something like

[[1]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
      [,1] [,2] [,3] [,4] [,5]
[1]    1    6    11   16    1

[[3]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1


Best, Muhammad Subianto


points.neighb <- function(p.class, list.nc, class.col) {
    ntuples <- nrow(p.class)
    instvec <- vector("list",length=ntuples)
    for (i in 1:ntuples) {
         # Thanks to Petr Pikal for this trick
         instvec[[i]]$class.diff <- (p.class[i,class.col] - 
list.nc[[i]][,class.col])!=0
         instvec[[i]]$class.same <- (p.class[i,class.col] - 
list.nc[[i]][,class.col])==0
    }
    instvec
}

points.diff <- function(p.class, list.nc) {
    ntuples <- length(list.nc)
    instvec <- vector("list",ntuples)
    for (i in 1:ntuples) {
         instvec[[i]]$point.diff <- list.nc[[i]][p.class[[i]]$class.diff,]
         instvec[[i]]$point.same <- list.nc[[i]][p.class[[i]]$class.same,]
    }
    instvec
}

# Thanks to Jim Holtman for this trick
delete.NULLs  <-  function(x.list){
     x.list[unlist(lapply(x.list, length) != 0)]
}

Dimitris Rizopoulos

2006-Aug-29 11:34 UTC

head link

[R] Remove empty list from list - remove only one row and make as matrix

try the following:

# a
dff[sapply(dff, is.matrix)]

# b
lapply(dff, function(x) if(!is.matrix(x)) rbind(x) else x)


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


----- Original Message ----- 
From: "Muhammad Subianto" <msubianto at gmail.com>
To: <r-help at stat.math.ethz.ch>
Sent: Tuesday, August 29, 2006 1:22 PM
Subject: Re: [R] Remove empty list from list - remove only one row and 
make as matrix

> Dear all,
> After I work around, I found in my list of data with only one row 
> which
> need to remove or make it as matrix.
> Here I write again my other toy example:
> x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5,
> 4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
> y <- list(c(1, -1, -1, 1, 1),c(1, -1, -1, -1, -1),c(1, 1, 1, 1, 
> 1),c(1,
> 1, -1, 1, -1),c(-1, -1, -1, -1, -1))
> ## Thanks to Gabor Grothendieck for this trick.
> ## SIMPLIFY? SIMPLIFY >< simplify
> xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)
>
> point.class <-
>
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
> class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
> pd.class <- points.diff(class.diffsame,xy.list)
>
> nc.test <- vector("list",length(pd.class))
> for (i in 1:length(pd.class)) {
>      nc.test[[i]] <- pd.class[[i]]$point.diff
> }
> nc.test
>
> # delete null/empty entries in a list
> dff <- delete.NULLs(nc.test)
> dff; str(dff)
> > dff
> [[1]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    4    9   14   19    1
> [3,]    5   10   15   20    1
>
> [[2]]
> [1]  1  6 11 16  1
>
> [[3]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    3    8   13   18   -1
> [2,]    5   10   15   20   -1
>
> >
>
> lapply(dff, nrow)
> > lapply(dff, nrow)
> [[1]]
> [1] 3
>
> [[2]]
> NULL
>
> [[3]]
> [1] 2
>
> >
>
> #I can use
> #dff[unlist(lapply(dff, nrow) == 1)] #2,3, etc
>
> I have two questions here:
> a. I need to remove dff[[2]]
> b. How to make it as matrix (in list). I mean the result something 
> like
>
> [[1]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16    1
> [2,]    4    9   14   19    1
> [3,]    5   10   15   20    1
>
> [[2]]
>      [,1] [,2] [,3] [,4] [,5]
> [1]    1    6    11   16    1
>
> [[3]]
>      [,1] [,2] [,3] [,4] [,5]
> [1,]    3    8   13   18   -1
> [2,]    5   10   15   20   -1
>
>
> Best, Muhammad Subianto
>
>
> points.neighb <- function(p.class, list.nc, class.col) {
>    ntuples <- nrow(p.class)
>    instvec <- vector("list",length=ntuples)
>    for (i in 1:ntuples) {
>         # Thanks to Petr Pikal for this trick
>         instvec[[i]]$class.diff <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])!=0
>         instvec[[i]]$class.same <- (p.class[i,class.col] -
> list.nc[[i]][,class.col])==0
>    }
>    instvec
> }
>
> points.diff <- function(p.class, list.nc) {
>    ntuples <- length(list.nc)
>    instvec <- vector("list",ntuples)
>    for (i in 1:ntuples) {
>         instvec[[i]]$point.diff <- 
> list.nc[[i]][p.class[[i]]$class.diff,]
>         instvec[[i]]$point.same <- 
> list.nc[[i]][p.class[[i]]$class.same,]
>    }
>    instvec
> }
>
> # Thanks to Jim Holtman for this trick
> delete.NULLs  <-  function(x.list){
>     x.list[unlist(lapply(x.list, length) != 0)]
> }
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

Muhammad Subianto

2006-Aug-29 12:14 UTC

head link

[R] Remove empty list from list - remove only one row and make as matrix

Dear all,
Dimitris, thanks for your great help and quick response.

Best, Muhammad Subianto


 > dff[sapply(dff, is.matrix)]
[[1]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1

 > lapply(dff, function(x) if(!is.matrix(x)) rbind(x) else x)
[[1]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    1    6   11   16    1
[2,]    4    9   14   19    1
[3,]    5   10   15   20    1

[[2]]
   [,1] [,2] [,3] [,4] [,5]
x    1    6   11   16    1

[[3]]
      [,1] [,2] [,3] [,4] [,5]
[1,]    3    8   13   18   -1
[2,]    5   10   15   20   -1

 >

On this day 29/08/2006 13:34, Dimitris Rizopoulos wrote:> try the following:
> 
> # a
> dff[sapply(dff, is.matrix)]
> 
> # b
> lapply(dff, function(x) if(!is.matrix(x)) rbind(x) else x)
> 
> 
> I hope it helps.
> 
> Best,
> Dimitris
> 
> ----
> Dimitris Rizopoulos
> Ph.D. Student
> Biostatistical Centre
> School of Public Health
> Catholic University of Leuven
> 
> Address: Kapucijnenvoer 35, Leuven, Belgium
> Tel: +32/(0)16/336899
> Fax: +32/(0)16/337015
> Web: http://med.kuleuven.be/biostat/
>      http://www.student.kuleuven.be/~m0390867/dimitris.htm
> 
> 
> ----- Original Message ----- 
> From: "Muhammad Subianto" <msubianto at gmail.com>
> To: <r-help at stat.math.ethz.ch>
> Sent: Tuesday, August 29, 2006 1:22 PM
> Subject: Re: [R] Remove empty list from list - remove only one row and 
> make as matrix
> 
> 
>> Dear all,
>> After I work around, I found in my list of data with only one row 
>> which
>> need to remove or make it as matrix.
>> Here I write again my other toy example:
>> x <- list(matrix(1:20, 5, 4),matrix(1:20, 5, 4),matrix(1:20, 5,
>> 4),matrix(1:20, 5, 4),matrix(1:20, 5, 4))
>> y <- list(c(1, -1, -1, 1, 1),c(1, -1, -1, -1, -1),c(1, 1, 1, 1, 
>> 1),c(1,
>> 1, -1, 1, -1),c(-1, -1, -1, -1, -1))
>> ## Thanks to Gabor Grothendieck for this trick.
>> ## SIMPLIFY? SIMPLIFY >< simplify
>> xy.list <- mapply(cbind, x, y, SIMPLIFY=FALSE)
>>
>> point.class <-
>>
t(cbind(c(10,20,15,4,-1),c(21,10,15,34,-1),c(11,13,6,3,1),c(7,5,5,2,1),c(8,9,5,12,-1)))
>> class.diffsame <- points.neighb(as.matrix(point.class), xy.list, 5)
>> pd.class <- points.diff(class.diffsame,xy.list)
>>
>> nc.test <- vector("list",length(pd.class))
>> for (i in 1:length(pd.class)) {
>>      nc.test[[i]] <- pd.class[[i]]$point.diff
>> }
>> nc.test
>>
>> # delete null/empty entries in a list
>> dff <- delete.NULLs(nc.test)
>> dff; str(dff)
>>> dff
>> [[1]]
>>      [,1] [,2] [,3] [,4] [,5]
>> [1,]    1    6   11   16    1
>> [2,]    4    9   14   19    1
>> [3,]    5   10   15   20    1
>>
>> [[2]]
>> [1]  1  6 11 16  1
>>
>> [[3]]
>>      [,1] [,2] [,3] [,4] [,5]
>> [1,]    3    8   13   18   -1
>> [2,]    5   10   15   20   -1
>>
>> lapply(dff, nrow)
>>> lapply(dff, nrow)
>> [[1]]
>> [1] 3
>>
>> [[2]]
>> NULL
>>
>> [[3]]
>> [1] 2
>>
>> #I can use
>> #dff[unlist(lapply(dff, nrow) == 1)] #2,3, etc
>>
>> I have two questions here:
>> a. I need to remove dff[[2]]
>> b. How to make it as matrix (in list). I mean the result something 
>> like
>>
>> [[1]]
>>      [,1] [,2] [,3] [,4] [,5]
>> [1,]    1    6   11   16    1
>> [2,]    4    9   14   19    1
>> [3,]    5   10   15   20    1
>>
>> [[2]]
>>      [,1] [,2] [,3] [,4] [,5]
>> [1]    1    6    11   16    1
>>
>> [[3]]
>>      [,1] [,2] [,3] [,4] [,5]
>> [1,]    3    8   13   18   -1
>> [2,]    5   10   15   20   -1
>>
>>
>> Best, Muhammad Subianto
>>
>>
>> points.neighb <- function(p.class, list.nc, class.col) {
>>    ntuples <- nrow(p.class)
>>    instvec <- vector("list",length=ntuples)
>>    for (i in 1:ntuples) {
>>         # Thanks to Petr Pikal for this trick
>>         instvec[[i]]$class.diff <- (p.class[i,class.col] -
>> list.nc[[i]][,class.col])!=0
>>         instvec[[i]]$class.same <- (p.class[i,class.col] -
>> list.nc[[i]][,class.col])==0
>>    }
>>    instvec
>> }
>>
>> points.diff <- function(p.class, list.nc) {
>>    ntuples <- length(list.nc)
>>    instvec <- vector("list",ntuples)
>>    for (i in 1:ntuples) {
>>         instvec[[i]]$point.diff <- 
>> list.nc[[i]][p.class[[i]]$class.diff,]
>>         instvec[[i]]$point.same <- 
>> list.nc[[i]][p.class[[i]]$class.same,]
>>    }
>>    instvec
>> }
>>
>> # Thanks to Jim Holtman for this trick
>> delete.NULLs  <-  function(x.list){
>>     x.list[unlist(lapply(x.list, length) != 0)]
>> }
>>

R help - Aug 2006 - Remove empty list from list

[R] Remove empty list from list

[R] Remove empty list from list

[R] Remove empty list from list

[R] Remove empty list from list

[R] Remove empty list from list - remove only one row and make as matrix

[R] Remove empty list from list - remove only one row and make as matrix

[R] Remove empty list from list - remove only one row and make as matrix