[R] Add function to each row excluding certain columns

[arun]

Hi,
Try:
example1<- as.matrix(read.table("example1.txt",header=TRUE,stringsAsFactors=FALSE,sep="\t",row.names=1,check.names=FALSE))
example2 <- example1 
example1New <- cbind(example1, `MAX without Restriction`=apply(example1[,1:4],1,max,na.rm=TRUE))
#or
library(matrixStats)
`MAX without Restriction`<- rowMaxs(example2[ ,colnames(example2)[!grepl("Restriction", colnames(example2))]],na.rm=TRUE)
 example2New <- cbind(example2, `MAX without Restriction`)
 identical(example1New,example2New)
#[1] TRUE


A.K.


Hello 

I've got a matrix of the following form 

        BARN	BCGE	BCVN	BEAN	Restriction 1	Restriction 2	Restriction 3	Restriction 4	Restriction 5 
alpha.1	0.000172449	7.87E-05	-0.003271044	0.000921609	9.28E-19	2.00E-05	-0.000608211	NA	NA 
alpha.2	0.000896744	0.000579453	-0.000623357	0.001260358	-1.36E-19	-5.22E-05	NA	NA	NA 
alpha.3	0.000832748	0.00076229	0.002170229	0.001159895	3.09E-19	-7.86E-05	NA	NA	NA 
alpha.4	0.000920545	NA	0.001680433	0.000459149	-3.08E-19	-3.59E-05	NA	NA	NA 
alpha.5	0.001385238	0.000527484	0.000593311	0.000549358	7.72E-19	-6.99E-05	NA	NA	NA 
alpha.6	0.000644262	0.000305714	-0.00044514	0.000407448	-9.68E-20	-5.56E-05	NA	NA	NA 
alpha.7	-0.00022808	-0.00017047	0.000109545	0.000601197	0	3.50E-05	NA	NA	NA 
alpha.8	-1.16E-05	-0.000105657	0.001403036	0.00058719	3.88E-19	8.64E-06	NA	NA	NA 
alpha.9	0.000633559	-4.33E-05	0.000724611	0.000841646	-4.82E-20	-3.29E-05	NA	NA	NA 

(see also file) 


Now I'd like to calculate the maximal value of each row, but
 exclude Restriction 1-5. An add a new column to the given matrix with 
the name 'MAX without Restriction' and the max of each row. 

I tried 

max<-apply(example1,1,function(x)max(x)) 
new<-cbind(example,max) 


but it gave a strange output, also I couldn't manage to exclude the columns Restriction 1-5. 

Thank you for your help!!