Since it is sometimes counter intuitive for working with ternary or other non-cartesian coordinates in the event that the the user wishes to place a text-geometry based on visual inspection, this geometry positions such text item at a fraction from x=[0,1] and y=[0,1] of the viewport in x and y cartesian coordinates.
geom_Text
understands the following aesthetics (required aesthetics are in bold):
label
x
y
alpha
angle
colour
family
fontface
hjust
lineheight
size
vjust
geom_text_viewport(mapping = NULL, data = NULL, stat = "identity", position = "identity", ..., hjust = "inward", vjust = "inward", parse = FALSE, check_overlap = FALSE, na.rm = FALSE, show.legend = NA, inherit.aes = TRUE)
aes
or
aes_
. If specified and inherit.aes = TRUE
(the
default), it is combined with the default mapping at the top level of the
plot. You must supply mapping
if there is no plot mapping.NULL
, the default, the data is inherited from the plot
data as specified in the call to ggplot
.
A data.frame
, or other object, will override the plot
data. All objects will be fortified to produce a data frame. See
fortify
for which variables will be created.
A function
will be called with a single argument,
the plot data. The return value must be a data.frame.
, and
will be used as the layer data.layer
. These are
often aesthetics, used to set an aesthetic to a fixed value, like
color = "red"
or size = 3
. They may also be parameters
to the paired geom/stat.TRUE
, text that overlaps previous text in the
same layer will not be plotted.FALSE
, the default, missing values are removed with
a warning. If TRUE
, missing values are silently removed.NA
, the default, includes if any aesthetics are mapped.
FALSE
never includes, and TRUE
always includes.FALSE
, overrides the default aesthetics,
rather than combining with them. This is most useful for helper functions
that define both data and aesthetics and shouldn't inherit behaviour from
the default plot specification, e.g. borders
.library(ggplot2) data(Feldspar) base = ggtern(data=Feldspar,aes(Ab,An,Or)) + geom_mask() + geom_point() + geom_text_viewport(x=0.5,y=0.5,label="Middle",color='red') + geom_text_viewport(x=1.0,y=1.0,label="Top Right",color='blue') + geom_text_viewport(x=0.0,y=0.0,label="Bottom Left",color='green') + geom_text_viewport(x=0.0,y=1.0,label="Top Left",color='orange') + geom_text_viewport(x=1.0,y=0.0,label="Bottom Right",color='magenta') basebase + geom_text_viewport(x=0.9,y=0.5,label="Clipping Turned Off",color='purple',hjust=0,clip='on')base + geom_text_viewport(x=0.9,y=0.5,label="Clipping Turned Off",color='purple',hjust=0,clip='off')