thr3ads.net - R help - [R] A question on List [Aug 2009]

If this information is useful, please help other people find it:
Share via:

RON70

2009-Aug-21 08:53 UTC

[R] A question on List

Suppose I have following list :

mat <- vector("list")
for (i in 1:4) mat[[i]] <- matrix(rnorm(25),5)
mat
> mat[[1]]
            [,1]       [,2]       [,3]       [,4]       [,5]
[1,] -1.27171814 -0.8087277 -0.4771356  0.6001265  0.9842248
[2,] -1.37337445  1.0754536 -1.6304287 -0.6854075 -0.6029390
[3,] -0.32393457 -0.8933633 -0.9077967  0.9738039 -3.0220266
[4,] -1.22184968 -1.2571625 -0.4064736 -1.6686981 -0.4896512
[5,] -0.09333244  1.4880530  1.6410411 -0.5489993  1.0939736

[[2]]
           [,1]       [,2]       [,3]       [,4]       [,5]
[1,] -1.0139178 -0.4817983 -0.2141111  0.1649356  1.7750268
[2,]  1.5544890  0.6345386  1.6307417 -2.0887206  1.8299279
[3,] -0.3575260 -0.6669547  0.5960779 -1.1091696 -0.2831409
[4,]  0.7742701  0.8313172  0.4178063 -2.5993914 -0.9920140
[5,] -0.6238547  0.8777678 -1.4249051 -0.4793574  0.5290309

[[3]]
           [,1]       [,2]         [,3]       [,4]        [,5]
[1,] -1.2833578  0.2271013 -1.605616640  0.3379672  0.86307678
[2,]  0.8928252 -0.2826024 -0.294600779  0.3659292 -0.06884467
[3,] -0.8237363  1.2258510  1.091578624  1.6907392 -0.42073560
[4,] -0.2537396  0.3662041  0.009558159  1.2127068 -1.14449393
[5,] -0.5001592  0.5390412  0.372628875 -0.9434233 -0.52022201

[[4]]
            [,1]         [,2]        [,3]       [,4]       [,5]
[1,]  0.55638191  2.000902039 -0.40155111  0.6214637  0.4044958
[2,]  0.06705861 -0.005629049  0.05144204  0.4910031 -0.2711823
[3,] -2.07173018 -0.210809259  0.22680564  0.5624870 -2.1322234
[4,]  0.04591303 -0.735466145 -0.13164334 -1.8873585 -1.2711131
[5,]  0.67454754  0.911601123  1.34304395  2.2798986 -0.5136242

Define another vector :

vect <- rnorm(4)


Now I want to do following calculation

for (i in 1:4) mat[[i]] <- mat[[i]] * vect[i]
mat


My question is, can I do previous calculation without having "for"
loop?

Thanks

-- 
View this message in context:
http://www.nabble.com/A-question-on-List-tp25075922p25075922.html
Sent from the R help mailing list archive at Nabble.com.

Petr PIKAL

2009-Aug-21 09:13 UTC

head link

[R] Odp: A question on List

Hi

 mapply("*", vect, mat, SIMPLIFY=F)

Regards
Petr

r-help-bounces at r-project.org napsal dne 21.08.2009 10:53:19:
> 
> Suppose I have following list :
> 
> mat <- vector("list")
> for (i in 1:4) mat[[i]] <- matrix(rnorm(25),5)
> mat
> 
> > mat
> [[1]]
>             [,1]       [,2]       [,3]       [,4]       [,5]
> [1,] -1.27171814 -0.8087277 -0.4771356  0.6001265  0.9842248
> [2,] -1.37337445  1.0754536 -1.6304287 -0.6854075 -0.6029390
> [3,] -0.32393457 -0.8933633 -0.9077967  0.9738039 -3.0220266
> [4,] -1.22184968 -1.2571625 -0.4064736 -1.6686981 -0.4896512
> [5,] -0.09333244  1.4880530  1.6410411 -0.5489993  1.0939736
> 
> [[2]]
>            [,1]       [,2]       [,3]       [,4]       [,5]
> [1,] -1.0139178 -0.4817983 -0.2141111  0.1649356  1.7750268
> [2,]  1.5544890  0.6345386  1.6307417 -2.0887206  1.8299279
> [3,] -0.3575260 -0.6669547  0.5960779 -1.1091696 -0.2831409
> [4,]  0.7742701  0.8313172  0.4178063 -2.5993914 -0.9920140
> [5,] -0.6238547  0.8777678 -1.4249051 -0.4793574  0.5290309
> 
> [[3]]
>            [,1]       [,2]         [,3]       [,4]        [,5]
> [1,] -1.2833578  0.2271013 -1.605616640  0.3379672  0.86307678
> [2,]  0.8928252 -0.2826024 -0.294600779  0.3659292 -0.06884467
> [3,] -0.8237363  1.2258510  1.091578624  1.6907392 -0.42073560
> [4,] -0.2537396  0.3662041  0.009558159  1.2127068 -1.14449393
> [5,] -0.5001592  0.5390412  0.372628875 -0.9434233 -0.52022201
> 
> [[4]]
>             [,1]         [,2]        [,3]       [,4]       [,5]
> [1,]  0.55638191  2.000902039 -0.40155111  0.6214637  0.4044958
> [2,]  0.06705861 -0.005629049  0.05144204  0.4910031 -0.2711823
> [3,] -2.07173018 -0.210809259  0.22680564  0.5624870 -2.1322234
> [4,]  0.04591303 -0.735466145 -0.13164334 -1.8873585 -1.2711131
> [5,]  0.67454754  0.911601123  1.34304395  2.2798986 -0.5136242
> 
> Define another vector :
> 
> vect <- rnorm(4)
> 
> 
> Now I want to do following calculation
> 
> for (i in 1:4) mat[[i]] <- mat[[i]] * vect[i]
> mat
> 
> 
> My question is, can I do previous calculation without having
"for" loop?
> 
> Thanks
> 
> -- 
> View this message in context: http://www.nabble.com/A-question-on-List-
> tp25075922p25075922.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at r-project.org 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.

baptiste auguie

2009-Aug-21 09:53 UTC

head link

[R] A question on List

Try this,

mat <- replicate(4, matrix(rnorm(25), 5), simpl=F)
mat

vect <- rnorm(4)

mapply( `*` , mat, vect, SIMPLIFY=F)

HTH,

baptiste

PS: I see someone replied already, but you might find replicate useful too

2009/8/21 RON70 <ron_michael70 at yahoo.com>:>
> Suppose I have following list :
>
> mat <- vector("list")
> for (i in 1:4) mat[[i]] <- matrix(rnorm(25),5)
> mat
>
>> mat
> [[1]]
> ? ? ? ? ? ?[,1] ? ? ? [,2] ? ? ? [,3] ? ? ? [,4] ? ? ? [,5]
> [1,] -1.27171814 -0.8087277 -0.4771356 ?0.6001265 ?0.9842248
> [2,] -1.37337445 ?1.0754536 -1.6304287 -0.6854075 -0.6029390
> [3,] -0.32393457 -0.8933633 -0.9077967 ?0.9738039 -3.0220266
> [4,] -1.22184968 -1.2571625 -0.4064736 -1.6686981 -0.4896512
> [5,] -0.09333244 ?1.4880530 ?1.6410411 -0.5489993 ?1.0939736
>
> [[2]]
> ? ? ? ? ? [,1] ? ? ? [,2] ? ? ? [,3] ? ? ? [,4] ? ? ? [,5]
> [1,] -1.0139178 -0.4817983 -0.2141111 ?0.1649356 ?1.7750268
> [2,] ?1.5544890 ?0.6345386 ?1.6307417 -2.0887206 ?1.8299279
> [3,] -0.3575260 -0.6669547 ?0.5960779 -1.1091696 -0.2831409
> [4,] ?0.7742701 ?0.8313172 ?0.4178063 -2.5993914 -0.9920140
> [5,] -0.6238547 ?0.8777678 -1.4249051 -0.4793574 ?0.5290309
>
> [[3]]
> ? ? ? ? ? [,1] ? ? ? [,2] ? ? ? ? [,3] ? ? ? [,4] ? ? ? ?[,5]
> [1,] -1.2833578 ?0.2271013 -1.605616640 ?0.3379672 ?0.86307678
> [2,] ?0.8928252 -0.2826024 -0.294600779 ?0.3659292 -0.06884467
> [3,] -0.8237363 ?1.2258510 ?1.091578624 ?1.6907392 -0.42073560
> [4,] -0.2537396 ?0.3662041 ?0.009558159 ?1.2127068 -1.14449393
> [5,] -0.5001592 ?0.5390412 ?0.372628875 -0.9434233 -0.52022201
>
> [[4]]
> ? ? ? ? ? ?[,1] ? ? ? ? [,2] ? ? ? ?[,3] ? ? ? [,4] ? ? ? [,5]
> [1,] ?0.55638191 ?2.000902039 -0.40155111 ?0.6214637 ?0.4044958
> [2,] ?0.06705861 -0.005629049 ?0.05144204 ?0.4910031 -0.2711823
> [3,] -2.07173018 -0.210809259 ?0.22680564 ?0.5624870 -2.1322234
> [4,] ?0.04591303 -0.735466145 -0.13164334 -1.8873585 -1.2711131
> [5,] ?0.67454754 ?0.911601123 ?1.34304395 ?2.2798986 -0.5136242
>
> Define another vector :
>
> vect <- rnorm(4)
>
>
> Now I want to do following calculation
>
> for (i in 1:4) mat[[i]] <- mat[[i]] * vect[i]
> mat
>
>
> My question is, can I do previous calculation without having
"for" loop?
>
> Thanks
>
> --
> View this message in context:
http://www.nabble.com/A-question-on-List-tp25075922p25075922.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org 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.
>


-- 
_____________________________

Baptiste Augui?

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

http://newton.ex.ac.uk/research/emag

R help - Aug 2009 - A question on List

[R] A question on List

[R] Odp: A question on List

[R] A question on List