Produces a (conditional) line plot of extended (log) odds ratios.

```
# S3 method for loddsratio
plot(x, baseline = TRUE, gp_baseline = gpar(lty = 2),
lines = TRUE, lwd_lines = 3,
confidence = TRUE, conf_level = 0.95, lwd_confidence = 2,
whiskers = 0, transpose = FALSE,
col = NULL, cex = 0.8, pch = NULL,
bars = NULL, gp_bars = gpar(fill = "lightgray", alpha = 0.5),
bar_width = unit(0.05, "npc"),
legend = TRUE, legend_pos = "topright", legend_inset = c(0, 0),
legend_vgap = unit(0.5, "lines"),
gp_legend_frame = gpar(lwd = 1, col = "black"),
gp_legend_title = gpar(fontface = "bold"),
gp_legend = gpar(), legend_lwd = 1, legend_size = 1,
xlab = NULL, ylab = NULL, xlim = NULL, ylim = NULL,
main = NULL, gp_main = gpar(fontsize = 12, fontface = "bold"),
newpage = TRUE, pop = FALSE, return_grob = FALSE,
add = FALSE, prefix = "", …)
# S3 method for loddsratio
lines(x, legend = FALSE, confidence = FALSE, cex = 0, …)
```

x

an object of class `loddsratio`

.

baseline

if `TRUE`

, a dashed line is plotted at a
value of 1 (in case of odds) or 0 (in case of log-odds).

gp_baseline

object of class `"gpar"`

used for the baseline.

lines

if `TRUE`

, the points are connected by lines (only
sensible if the variable represented by the x-axis is ordinal).

lwd_lines

Width of the connecting lines (in `char`

units).

confidence

logical; shall confindence intervals be plotted?

conf_level

confidence level used for confidence intervals.

lwd_confidence

Line width of the confidence interval bars (in `char`

units).

whiskers

width of the confidence interval whiskers.

transpose

if `TRUE`

, the plot is transposed.

col

character vector specifying the colors of the fitted
lines, by default chosen with `rainbow_hcl`

.

cex

size of the plot symbols (in lines).

pch

character or numeric vector of symbols used for plotting the (possibly conditioned) observed values, recycled as needed.

bars

logical; shall bars be plotted additionally to the points?
Defaults to `TRUE`

in case of only one conditioning variable.

gp_bars

object of class `"gpar"`

used for the bars.

bar_width

Width of the bars, if drawn.

legend

logical; if `TRUE`

(default), a legend is drawn.

legend_pos

numeric vector of length 2, specifying x and y
coordinates of the legend, or a character string (e.g., `"topleft"`

,
`"center"`

etc.). Defaults to `"topleft"`

if the fitted curve's slope is
positive, and `"topright"`

else.

legend_inset

numeric vector or length 2 specifying the inset from the legend's x and y coordinates in npc units.

legend_vgap

vertical space between the legend's line entries.

gp_legend_frame

object of class `"gpar"`

used for the
legend frame.

gp_legend_title

object of class `"gpar"`

used for the
legend title.

gp_legend

object of class `"gpar"`

used for the
legend defaults.

legend_lwd

line width used in the legend for the different groups.

legend_size

size used for the group symbols (in char units).

xlab

label for the x-axis. Defaults to `"Strata"`

if
`transpose`

is `FALSE`

.

ylab

label for the y-axis. Defaults to `"Strata"`

if
`transpose`

is `TRUE`

.

xlim

x-axis limits. Ignored if `transpose`

is `FALSE`

.

ylim

y-axis limits. Ignored if `transpose`

is `TRUE`

.

main

user-specified main title.

gp_main

object of class `"gpar"`

used for the main title.

newpage

logical; if `TRUE`

, the plot is drawn on a new page.

pop

logical; if `TRUE`

, all newly generated viewports are
popped after plotting.

return_grob

logical. Should a snapshot of the display be returned as a grid grob?

add

logical; should the plot added to an existing log odds ratio plot?

prefix

character string used as prefix for the viewport name.

…

other graphics parameters (see `par`

).

if `return_grob`

is `TRUE`

, a grob object corresponding to
the plot. `NULL`

(invisibly) else.

The function basically produces conditioned line plots of the (log)
odds ratios structure provided in `x`

.

The `lines`

method can be used to overlay different plots (for
example, observed and expected values).

`cotabplot`

can be used for stratified analyses (see examples).

M. Friendly (2000),
*Visualizing Categorical Data*.
SAS Institute, Cary, NC.

# NOT RUN { ## 2 x 2 x k cases data(CoalMiners, package = "vcd") lor_CM <- loddsratio(CoalMiners) plot(lor_CM) lor_CM_df <- as.data.frame(lor_CM) # fit linear models using WLS age <- seq(20, 60, by = 5) lmod <- lm(LOR ~ age, weights = 1 / ASE^2, data = lor_CM_df) grid.lines(seq_along(age), fitted(lmod), gp = gpar(col = "blue", lwd = 2), default.units = "native") qmod <- lm(LOR ~ poly(age, 2), weights = 1 / ASE^2, data = lor_CM_df) grid.lines(seq_along(age), fitted(qmod), gp = gpar(col = "red", lwd = 2), default.units = "native") ## 2 x k x 2 lor_Emp <-loddsratio(Employment) plot(lor_Emp) ## 4 way tables data(Punishment, package = "vcd") mosaic(attitude ~ age + education + memory, data = Punishment, highlighting_direction="left", rep = c(attitude = FALSE)) # visualize the log odds ratios, by education plot(loddsratio(~ attitude + memory | education, data = Punishment)) # visualize the log odds ratios, by age plot(loddsratio(~ attitude + memory | age, data = Punishment)) # visualize the log odds ratios, by age and education plot(loddsratio(~ attitude + memory | age + education, data = Punishment)) # same, transposed plot(loddsratio(~ attitude + memory | age + education, data = Punishment), transpose = TRUE) # alternative visualization methods image(loddsratio(Freq ~ ., data = Punishment)) tile(loddsratio(Freq ~ ., data = Punishment)) ## cotabplots for more complex tables cotabplot(Titanic, cond = c("Age","Sex"), panel = cotab_loddsratio) cotabplot(Freq ~ opinion + grade + year | gender, data = JointSports, panel = cotab_loddsratio) cotabplot(Freq ~ opinion + grade | year + gender, data = JointSports, panel = cotab_loddsratio) # }