CODEWITHSUNDEEP
rmatrixalphabetical
melatonin15
melatonin15

Reputation: 2269

Reordering matrix columns based on specific prefix in few column names in R

I have a matrix in R with column names. 

> colnames(m)
 [1] "caz_RNAi1_R1"     "caz_RNAi2_R1"     "cg1316_RNAi1_R1"  "cg1316_RNAi2_R1"  "cg4612_RNAi1_R1" 
 [6] "cg4612_RNAi2_R1"  "Dp1_RNAi1_R1"     "Dp1_RNAi2_R1"     "fmr1_RNAi1_R1"    "fmr1_RNAi2_R1"   
[11] "GFP_RNAi1_R1"     "GFP_RNAi2_R1"     "GFP_RNAi3_R1"     "GFP_RNAi4_R1"     "GFP_RNAi5_R1"    
[16] "GFP_RNAi6_R1"     "hrb87f_RNAi1_R1"  "hrb87f_RNAi2_R1"  "hrb98de_RNAi1_R1" "hrb98de_RNAi2_R1"

Now, some of the column names has prefix GFP. I want to reorder the matrix columns so that the columns having this prefix in their names would be the beginning columns and rest of the columns would be alphabetically ordered among themselves.

So colnames(m) should be ordered something like:

"GFP_a", "GFP_b", "GFP_c",..."GFP_z", "a", "b","c","d", ....

What's the way to do this?

Upvotes: 3

Views: 1123

Answers (2)

akrun
akrun

Reputation: 887078

You could do

 m[order(-(grepl('^GFP', m))+1L)]

where m is from @Mamoun Benghezal's post. In the example, it is already ordered alphabetically, but in case it is not

 set.seed(24)
 m1 <-sample(m)
 m1[order(m1)][order(-(grepl('^GFP',m1[order(m1)]))+1L)]

Upvotes: 4

Mamoun Benghezal
Mamoun Benghezal

Reputation: 5314

you can try this

m <-  c("caz_RNAi1_R1", "caz_RNAi2_R1", "cg1316_RNAi1_R1", "cg1316_RNAi2_R1", "cg4612_RNAi1_R1",
        "cg4612_RNAi2_R1", "Dp1_RNAi1_R1", "Dp1_RNAi2_R1", "fmr1_RNAi1_R1", "fmr1_RNAi2_R1",
        "GFP_RNAi1_R1", "GFP_RNAi2_R1", "GFP_RNAi3_R1", "GFP_RNAi4_R1", "GFP_RNAi5_R1",
        "GFP_RNAi6_R1", "hrb87f_RNAi1_R1",  "hrb87f_RNAi2_R1",  "hrb98de_RNAi1_R1", "hrb98de_RNAi2_R1")
sort(m[grep(pattern="^GFP", x = m )]) # beginning with GFP
## [1] "GFP_RNAi1_R1" "GFP_RNAi2_R1" "GFP_RNAi3_R1" "GFP_RNAi4_R1" "GFP_RNAi5_R1" "GFP_RNAi6_R1"
sort(m[-grep(pattern="^GFP", x = m )]) # do not begin by GFP
##     [1] "caz_RNAi1_R1"     "caz_RNAi2_R1"     "cg1316_RNAi1_R1"  "cg1316_RNAi2_R1"  "cg4612_RNAi1_R1"  "cg4612_RNAi2_R1"  "Dp1_RNAi1_R1"     "Dp1_RNAi2_R1"     "fmr1_RNAi1_R1"    "fmr1_RNAi2_R1"   
##    [11] "hrb87f_RNAi1_R1"  "hrb87f_RNAi2_R1"  "hrb98de_RNAi1_R1" "hrb98de_RNAi2_R1"
c(sort(m[grep(pattern="^GFP", x = m )]),  sort(m[-grep(pattern="^GFP", x = m )])) # ordered columns

Upvotes: 3

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