Core-generating function for `strucplot`

returning a function
producing association plots.

```
struc_assoc(compress = TRUE, xlim = NULL, ylim = NULL,
yspace = unit(0.5, "lines"), xscale = 0.9, gp_axis = gpar(lty = 3))
```

A function with arguments:

- residuals
table of residuals.

- observed
not used by

`struc_assoc`

.- expected
table of expected frequencies.

- spacing
object of class

`"unit"`

specifying the space between the tiles.- gp
list of

`gpar`

objects used for the drawing the tiles.- split_vertical
vector of logicals indicating, for each dimension of the table, the split direction.

- compress
logical; if

`FALSE`

, the space between the rows (columns) are chosen such that the*total*heights (widths) of the rows (column) are all equal. If`TRUE`

, the space between the rows and columns is fixed and hence the plot is more “compressed”.- xlim
either a \(2 \times k\) matrix of doubles, \(k\) the number of total columns of the plot, or a recycled vector from which such a matrix will be constructed. The columns of

`xlim`

correspond to the columns of the association plot, the rows describe the column ranges (minimums in the first row, maximums in the second row). If`xlim`

is`NULL`

, the ranges are determined from the residuals according to`compress`

(if`TRUE`

: widest range from each column, if`FALSE`

: from the whole association plot matrix).- ylim
either a \(2 \times k\) matrix of doubles, \(k\) the number of total rows of the plot, or a recycled vector from which such a matrix will be constructed. The columns of

`ylim`

correspond to the rows of the association plot, the rows describe the column ranges (minimums in the first row, maximums in the second row). If`ylim`

is`NULL`

, the ranges are determined from the residuals according to`compress`

(if`TRUE`

: widest range from each row, if`FALSE`

: from the whole association plot matrix).- xscale
scale factor resizing the tile's width, thus adding additional space between the tiles.

- yspace
object of class

`"unit"`

specifying additional space separating the rows.- gp_axis
object of class

`"gpar"`

specifying the visual aspects of the tiles' baseline.

David Meyer David.Meyer@R-project.org

This function is usually called by `strucplot`

(typically when
called by `assoc`

) and returns a function used by
`strucplot`

to produce association plots.

Cohen, A. (1980),
On the graphical display of the significant components in a two-way
contingency table.
*Communications in Statistics---Theory and Methods*, **A9**,
1025--1041.

Friendly, M. (1992),
Graphical methods for categorical data.
*SAS User Group International Conference Proceedings*, **17**,
190--200.
http://datavis.ca/papers/sugi/sugi17.pdf

Meyer, D., Zeileis, A., and Hornik, K. (2006),
The strucplot framework: Visualizing multi-way contingency tables with
vcd.
*Journal of Statistical Software*, **17(3)**, 1-48.
tools:::Rd_expr_doi("10.18637/jss.v017.i03") and available as
`vignette("strucplot")`

.

`assoc`

,
`strucplot`

,
`structable`

```
## UCB Admissions
data("UCBAdmissions")
ucb <- aperm(UCBAdmissions)
## association plot for conditional independence
strucplot(ucb, expected = ~ Dept * (Admit + Gender),
core = struc_assoc(ylim = c(-4, 4)), labeling_args = list(abbreviate = c(Admit = 3)))
```

Run the code above in your browser using DataLab