get_valL {lazy.tools}

R Documentation

Get Values from a List Consisting of Data Frames

Description

Get Values from a List Consisting of Data Frames

Usage

get_valL(L, s1 = NULL, s2 = NULL, s3 = NULL, simplify = 1)

put_valL(L, s1 = NULL, s2 = NULL, s3 = NULL) <- value

Arguments

L	A list of data frames
s1	Vector consisting of the subscripts for the 1st dimension
s2	Vector consisting of the subscripts for the 2nd dimension
s3	Vector consisting of the subscripts for the 3rd dimension
simplify	= 0 to leave the result of get_valL unsimplified (list)
value	The value to be assigned. Either a vector or a matrix.

Details

It is assumed that L is a list consisting of several data frames. and the third subscript, s3 is for the list.
Therefore, get_valL(L,,,s3) with scalar s3 is equivalent to L[[s3]]
and get_valL(L,,,2:3) returns the 2nd and the 3rd data frames in a list.

s1,s2,s3 can be a set of vectors consisting of row/col/list names.

When some of the subscripts are out of range, only the valid ones will be used.

The result will be simplified to a matrix or vector if possible.
When length(s1)==1, the result will be a length(L) x ncol(L[[1]]) matrix.
When length(s2)==1, the result will be a ncol(L[[1]]) x length(L) matrix.

Value

get_valL(L, s1,s2,s3) returns (s1,s2) element(s) of the s3-th data frame(s).
put_valL(L, s1,s2,s3) <- value replaces the s1,s2 element(s) of the data frame(s) specified by s3 with value.

Examples

L0 <- list( A=data.frame(demomat(3,2)*10+1)
          , B=data.frame(demomat(4,3)*10+2)
          , C=data.frame(demomat(5,4)*10+3)
         )
L <- L0
get_valL( L, ,,2 ) # should be equal to get_valL( L, ,,"B" )
get_valL( L, 2, )  # should be equal to get_valL( L, "r2",, )
get_valL( L, ,2 )  # should be equal to get_valL( L, , "c2", )
get_valL( L, c(1,3),,3:2 )
get_valL( L, c(1,3),, c("B","A") )

L <- L0; put_valL(L, 1:2,1:2,3) <- 0;                  Print(L)
L <- L0; put_valL(L, 1:2,1:2,c("C","A")) <- 0;         Print(L)
L <- L0; put_valL(L, 3:5,2:4,) <- 0;                   Print(L)
L <- L0; put_valL(L, 3:5,2:4,2) <- 0;                  Print(L)
L <- L0; put_valL(L, 1:4,1,2:3) <- 1:4;                Print(L)
L <- L0; put_valL(L, 1:2,2:3,2:3) <- demomat(2,2)*100; Print(L)

# effect of simplify
L0 <- list( A=data.frame(demomat(3,4)*10+1)
          , B=data.frame(demomat(3,4)*10+2)
          , C=data.frame(demomat(3,4)*10+3)
         )
L <- L0
get_valL( L, ,,2 )
get_valL( L, ,,2, simplify=0 )
get_valL( L, 2, )
get_valL( L, 2,, simplify=0 )
get_valL( L, ,2 )
get_valL( L, ,2, simplify=0 )

# When the selected elements are scalars, the result is a column vector.
get_valL(L0,1:2,1) # matrix
get_valL(L0,1,1)   # col vector
get_valL(L0,1,1:2) # matrix

# mixed type variables in a data frame
A <- data.frame(demomat(3,4)*10+1)
A[,2] <- paste("c",as.character(A[,2]),sep="")
B <- data.frame(demomat(3,4)*10+2)
B[,2] <- paste("c",as.character(B[,2]),sep="")
C <- data.frame(demomat(3,4)*10+3)
C[,2] <- paste("c",as.character(C[,2]),sep="")
L <- list(A=A,B=B,C=C)

get_valL( L, 2, )
get_valL( L, , 2 )

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