[R] Finding all rows of a matrix equal to vector

[Berend Hasselman]

Sebastian Lerch wrote:
> 
> Hi everyone,
> 
> my question might be very trivial, but I could not come up with an
> answer...
> 
> I want to find out how often a matrix contains a certain vector as row:
> 
> x1<-c(1,2,3)
> x2<-c(1,5,6)
> x3<-c(7,8,9)
> A<-matrix(c(rep(x1,5),rep(x2,5),rep(x3,5),rep(x1,5)),nrow=20,ncol=3,byrow=T)
> 
> How can I find out, how many times x1 is a row of A?
> 
> 

v <- apply(A,1, FUN = function(x)identical(x,x1)) 
v
sum(v)

v <- apply(A,1, FUN = function(x)all(zapsmall(x-x1)==0)) 
v
sum(v)


Berend


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