l_getSavedStates {loon}

Retrieve saved plot states from the named file.

Description

l_getSavedStates reads a file created by l_saveStates() containing the saved info states of a loon plot returning a loon object of class "l_savedStates". This is helpful, for example, when using RMarkdown or some other notebooking facility to recreate an earlier saved loon plot so as to present it in the document.

Note that if the plot saved was an "l_compound" then l_getSavedStates will return a list of the plots with each list item being the saved states of the corresponding plots.

Usage

l_getSavedStates(file = stop("missing name of file"), ...)

Arguments

file

a connection or the name of the file where the "l_savedStates" R object is to be read from (as in readRDS().

...

further arguments passed to readRDS().

Value

a list of class 'l_savedStates' containing the states and their values. Also has an attribute 'l_plot_class' which contains the class vector of the plot 'p'

See Also

l_getSavedStates l_copyStates l_info_states readRDS saveRDS

Examples

if(interactive()){
#
# Suppose you have some plot that you created like
p <- l_plot(iris, showGuides = TRUE)
#
# and coloured groups by hand (using the mouse and inspector)
# so that you ended up with these colours:
p["color"] <- rep(c( "lightgreen", "firebrick","skyblue"),
                  each = 50)
#
# Having determined the colours you could save them (and other states)
# in a file of your choice, here some tempfile:
myFileName <- tempfile("myPlot", fileext = ".rds")
#
# Save the named states of p
l_saveStates(p,
             states = c("color", "active", "selected"),
             file = myFileName)
#
# These can later be retrieved and used on a new plot
# (say in RMarkdown) to set the new plot's values to those
# previously determined interactively.
p_new <- l_plot(iris, showGuides = TRUE)
p_saved_info <- l_getSavedStates(myFileName)
#
# We can tell what kind of plot was saved
attr(p_saved_info, "l_plot_class")
#
# The result is a list of class "l_savedStates" which
# contains the names of the
p_new["color"] <- p_saved_info$color
#
# The result is that p_new looks like p did
# (after your interactive exploration)
# and can now be plotted as part of the document
plot(p_new)
#
# For compound plots, the info_states are saved for each plot
pp <- l_pairs(iris)
myPairsFile <- tempfile("myPairsPlot", fileext = ".rds")
#
# Save the names states of pp
l_saveStates(pp,
             states = c("color", "active", "selected"),
             file = myPairsFile)
pairs_info <-  l_getSavedStates(myPairsFile)
#
# For compound plots, the info states for all constitutent
# plots are saved.  The result is a list of class "l_savedStates"
# whose elements are the named plots as "l_savedStates"
# themselves.
#
# The names of the plots which were saved
names(pairs_info)
#
# And the names of the info states whose values were saved for
# the first plot
names(pairs_info$x2y1)
#
# While it is generally recommended to access (or assign) saved
# state values using the $ sign accessor, paying attention to the
# nested list structure of an "l_savedStates" object (especially for
# l_compound plots), R's square bracket notation [] has also been
# specialized to allow a syntactically simpler (but less precise)
# access to the contents of an l_savedStates object.
#
# For example,
p_saved_info["color"]
#
# returns the saved "color" as a vector of colours.
#
# In contrast,
pairs_info["x2y1"]
# returns the l_savedStates object of the states of the plot named "x2y1",
# but
pairs_info["color"]
# returns a LIST of colour vectors, by plot as they were named in pairs_info
#
# As a consequence, the following two are equivalent,
pairs_info["x2y1"]["color"]
# finds the value of "color" from an "l_savedStates" object
# whereas
pairs_info["color"][["x2y1"]]
# finds the value of "x2y1" from a "list" object
#
# Also, setting a state of an "l_savedStates" is possible
# (though not generally recommended; better to save the states again)
#
p_saved_info["color"] <- rep("red", 150)
# changes the saved state "color" on p_saved_info
# whereas
pairs_info["color"] <- rep("red", 150)
# will set the red color for any plot within pairs_info having "color" saved.
# In this way the assignment function via [] is trying to be clever
# for l_savedStates for compound plots and so may have unintentional
# consequences if the user is not careful.

# Generally, one does not want/need to change the value of saved states.
# Instead, the states would be saved again from the interactive plot
# if change is necessary.
# Alternatively, more nuanced and careful control is maintained using
# the $ selectors for lists.
}