decideMfrow function

Decide plot panel rows, columns for graphics::par(mfrow)

decideMfrow(
  n,
  method = c("aspect", "wide", "tall"),
  doTest = FALSE,
  xyratio = 1,
  trimExtra = TRUE,
  ...
)

Arguments

• n: integer number of plot panels

• method: character string indicating the type of layout to favor.

  • "aspect": uses the device size and aspect ratio of the plot to try to maintain roughly square plot panels.
  • "wide": tries to keep the columns and rows similar, erring on the side of more columns than rows.
  • "tall": tries to keep the columns and rows similar, erring on the side of more rows than columns.

• doTest: logical whether to provide a visual test. Note that n is required as the number of plot panels requested.

• xyratio: numeric default 1, with the desired target x-to-y ratio. For example, to have plots slightly wider (x width) than tall (y height), use xyratio=1.3. The observed device aspect ratio is divided by xyratio to determine the target aspect ratio of plot panels.

• trimExtra: logical default TRUE, whether to trim blank rows or columns in the expected layout when it would be entirely blank. For example, n=4 may produce c(3, 2) output to meet the desired aspect ratio, however with trimExtra=TRUE it would be reduced to c(2, 2) to minimize unused whitespace.

• ...: additional parameters are ignored.

Returns

numeric vector length=2, with the recommended number of plot rows and columns, respectively. It is intended to be used directly in this form: graphics::par("mfrow"=decideMfrow(n=5))

Details

This function returns the recommended rows and columns of panels to be used in graphics::par("mfrow") with R base plotting. It attempts to use the device size and plot aspect ratio to keep panels roughly square. For example, a short-wide device would have more columns of panels than rows; a tall-thin device would have more rows than columns.

The doTest=TRUE argument will create n number of panels with the recommended layout, as a visual example.

Note this function calls getPlotAspect(), therefore if no plot device is currently open, the call to graphics::par() will open a new graphics device.

Examples

# display a test visualization showing 6 panels
withr::with_par(list("mar"=c(2, 2, 2, 2)), {
decideMfrow(n=6, doTest=TRUE);
})

# use a custom target xyratio of plot panels
withr::with_par(list("mar"=c(2, 2, 2, 2)), {
decideMfrow(n=3, xyratio=3, doTest=TRUE);
})

# a manual demonstration creating 6 panels
n <- 6;
withr::with_par(list(
   "mar"=c(2, 2, 2, 2),
   "mfrow"=decideMfrow(n)), {
for(i in seq_len(n)){
   nullPlot(plotAreaTitle=paste("Plot", i));
}
})

See Also

Other jam plot functions: adjustAxisLabelMargins(), coordPresets(), drawLabels(), getPlotAspect(), groupedAxis(), imageByColors(), imageDefault(), minorLogTicksAxis(), nullPlot(), plotPolygonDensity(), plotRidges(), plotSmoothScatter(), shadowText(), shadowText_options(), showColors(), sqrtAxis(), usrBox()