| playPointInput {playwith} | R Documentation |
Part of the playwith Application Programming Interface.
playPointInput(playState = playDevCur(), prompt) playLineInput(playState = playDevCur(), prompt) playRectInput(playState = playDevCur(), prompt)
playState |
a playState object representing the plot, window and device. |
prompt |
text to display in the prompt. |
playPointInput is similar to locator, but
returns native coordinates in whichever plot space was clicked on.
Device coordinates and normalised device coordinates are also available.
playRectInput and playLineInput allow the user to
interactively draw a rectangle or line.
All these functions return NULL if the user cancelled (e.g. by right-clicking).
The return value is a list with:
|
character, specifies the plot space in which the user clicked or dragged.
See the space argument to playDo.
|
|
native coordinates of the point or shape in space.
A list with numeric vectors x and y.
For a rectangle or line, these are length 2 where the first element
refers to the start of the drag motion. For a point these are length 1.
If space is "page", this is NULL.
|
|
device coordinates of the point or shape (pixels). |
|
normalised device coordinates of the point or shape. |
|
logical, whether it was a click
(so probably should not be treated as a rectangle or line).
This is not returned by playPointInput.
|
|
a flag representing which modifier keys were
pressed during the click (or at the end of a drag).
E.g. to test for Shift key:
if (foo$modifiers & GdkModifierType["shift-mask"]).
See enums-and-flags.
|
Felix Andrews felix@nfrac.org
if (interactive()) {
library(lattice)
playwith(xyplot(Sepal.Width ~ Petal.Width | Species, data = iris))
playPointInput()
playRectInput()
}