moffset {VGAM} | R Documentation

## Matrix Offset

### Description

Modify a matrix by shifting successive elements.

### Usage

    moffset(mat, roffset = 0, coffset = 0, postfix = "",
            rprefix = "Row.", cprefix = "Col.")

### Arguments

`mat` | Data frame or matrix. This ought to have at least three rows and three columns. The elements are shifted in the order of `c(mat)`, i.e., going down successive columns, as the columns go from left to right. Wrapping of values is done.

`roffset, coffset`

Numeric or character. If numeric, the amount of shift (offset) for each row and column. The default is no change to `mat`. If character, the offset is computed by matching with the row or column names. For example, for the `alcoff`, put `roffset = "6"` means that we make an effective day's dataset start from 6:00 am, and this wraps around to include midnight to 05.59 am on the next day.

`postfix` | Character. Modified rows and columns are renamed by pasting this argument to the end of each name. The default is no change.
`rprefix, cprefix` | Same as `rcim`.

### Details

This function allows a matrix to be rearranged so that element (`roffset` + 1, `coffset` + 1) becomes the (1, 1) element. The elements are assumed to be ordered in the same way as the elements of `c(mat)`,

This function is applicable to, e.g., `alcoff`, where it is useful to define the effective day as starting at some other hour than midnight, e.g., 6.00am. This is because partying on Friday night continues on into Saturday morning, therefore it is more interpretable to use the effective day when considering a daily effect.

This is a data preprocessing function for `rcim` and `plotrcim0`. The differences between `Rcim` and `moffset` is that `Rcim` only reorders the level of the rows and columns so that the data is shifted but not moved. That is, a value in one row stays in that row, and ditto for column. But in `moffset` values in one column can be moved to a previous column. See the examples below.

### Value

A matrix of the same dimensional as its input.

### Note

The input `mat` should have row names and column names.

### Author(s)

T. W. Yee, Alfian F. Hadi.

### See Also

`Rcim`, `rcim`, `plotrcim0`, `alcoff`, `crashi`.

### Examples

    moffset(alcoff, 3, 2, "*")  # Some day's data is moved to previous day.
    Rcim(alcoff, 3 + 1, 2 + 1)  # Data does not move as much.
    alcoff  # Original data
    moffset(alcoff, 3, 2, "*") - Rcim(alcoff, 3+1, 2+1)  # Note the differences

    # An 'effective day' data set:
    alcoff.e <- moffset(alcoff, roffset = "6", postfix = "*")
    fit.o <- rcim(alcoff)    # default baselines are first row and col
    fit.e <- rcim(alcoff.e)  # default baselines are first row and col

    ## Not run:  par(mfrow = c(2, 2), mar = c(9, 4, 2, 1))
    plot(fit.o, rsub = "Not very interpretable", csub = "Not very interpretable")
    plot(fit.e, rsub = "More interpretable", csub = "More interpretable")

    ## End(Not run)

    # Some checking
    all.equal(moffset(alcoff), alcoff)  # Should be no change
    moffset(alcoff, 1, 1, "*")
    moffset(alcoff, 2, 3, "*")
    moffset(alcoff, 1, 0, "*")
    moffset(alcoff, 0, 1, "*")
    moffset(alcoff, "6", "Mon", "*")  # This one is good

    # Customise row and column baselines
    fit2 <- rcim(Rcim(alcoff.e, rbaseline = "11", cbaseline = "Mon*"))

[Package VGAM version 1.1-1 Index]