[R] Fill an empty matrix with a function

[Maximilian Eckert]

Dear Sir oder Madam,

 

I am currently writing my master thesis and I am struggling with R:

 

I have created an empty matrix (M) which has months as row.names and stocks
as column.names and now I want to fill this matrix with values from another
matrix (T). The matrix T has also months as row.names and stocks as
column.names however here I have several  values for each month. Now I want
to count the values which have values bigger or equal to zero (plus 1) and
add them to my matrix M:

 

If I do it manually it would look like: 

 

M[,1] <- t(array((colSums(T[1:22,] > 0))+1))  #here in Matrix T I have 22
values for the month January 

M[,2] <- t(array((colSums(T[23:53,] > 0))+1)) #here in Matrix T I have 30
values for the monh February 

 

Is there a way to do this without a loop as I have a very large data set? I
tried to merge it however it did not work:

 

merge.default(as.data.frame(M), as.data.frame(T), by = "row.names",
function(x){colSums(T[,]>0)+1})

 

Thank you very much,

 

Max 


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