[R] compare and count data

Jim Lemon jim at bitwrit.com.au
Mon Jan 21 08:16:50 CET 2013


On 01/21/2013 04:39 PM, Roslina Zakaria wrote:
> Dear r-users,
>
> I have these data below:
>
> I would like to compare each column with a certain value and count how many in each column less than that specified value.
>
> odd column (1,3,5) will compare with 1.61 and even column (2,4,6) will compare with 75 and I would like to count how many for each column.
>
>
> I tried these below but it give me just one set of data.
>
> critical<- c(1.61,75.89, 1.61, 75.89, 1.61, 75.89)   ; critical
> pilih<- mydata[mydata<  critical] ; pilih
> jumlah<- length(pilih)   ; jumlah
> kuasa<- 1 - (jumlah/1000);  kuasa
>
>> head(mydata,20)
>           V1       V1       V1       V1
> 1  3.014505 62.96425 3.014505 138.0673
> 2  2.817503 56.03400 2.817503 133.3411
> 3  2.976227 47.12192 2.976227 139.2438
> 4  2.825495 75.05284 2.825495 129.2959
> 5  2.793500 52.75190 2.793500 130.9874
> 6  3.006333 54.56210 3.006333 136.2982
> 7  3.245833 71.31358 3.245833 150.0974
> 8  2.559980 64.28300 2.559980 114.5395
> 9  2.548456 69.48727 2.548456 118.7383
> 10 2.715040 58.64134 2.715040 123.0574
> 11 2.799652 58.96281 2.799652 126.9216
> 12 2.900839 75.43427 2.900839 131.6100
> 13 3.183844 63.57657 3.183844 143.5530
> 14 2.792940 63.04534 2.792940 120.1010
> 15 3.229830 71.09790 3.229830 136.6931
> 16 3.528115 68.64850 3.528115 156.0135
> 17 2.973711 58.45141 2.973711 128.6738
> 18 2.518891 53.62788 2.518891 110.6072
> 19 2.848493 79.29142 2.848493 127.6110
> 20 2.971362 57.81008 2.971362 129.5411
> 	[[alternative HTML version deleted]]
>
>
Hi Roslina,
I think what you may want is something like this:

colSums(t(apply(mydata,1,FUN="<",rep(c(1.61,75),
  length.out=dim(mydata)[2]/2))))

Jim



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