| colmean, colmin, colmax, colrange, colvar, colsd, colprod, colsum, colna {bigmemory} | R Documentation |
These functions operate on columns of the big.matrix.
colmean(x, cols, na.rm) colmin(x, cols, na.rm) colmax(x, cols, na.rm) colrange(x, cols, na.rm) colvar(x, cols, na.rm) colsd(x, cols, na.rm) colsum(x, cols, na.rm) colprod(x, cols, na.rm) colna(x, cols)
x |
a big.matrix. |
cols |
a scalar or vector of column(s) to be summarized. |
na.rm |
if TRUE, remove NA values before summarizing. |
These functions essentially apply summary functions to each column (or
each specified column) of the big.matrix in turn.
For colrange, a matrix with two columns and length(cols)
rows; column 1 contains the minimum, and column 2 contains the maximum for
that column. The other functions return vectors of length length(cols).
John W. Emerson and Michael J. Kane
x <- as.big.matrix(matrix(sample(1:10, 20, replace=TRUE), 5, 4))
colnames(x) <- c("a", "b", "c", "d")
x[,]
mean(x)
colmean(x)
colmin(x)
colmin(x, 1)
colmax(x)
colmax(x, "b")
colsd(x)
colrange(x)
range(x)
colsum(x)
colprod(x)