export_graph_start: Graph export with garanteed text size

In fplot: Automatic Distribution Graphs Using Formulas

Graph export with garanteed text size

Description

This function facilitates graph exportation by taking into account the final destination of the graph (typically a document) and allowing the user to use point size, an intuitive unit in written documents, as the graph scaler. Once located in the final document, the text of the graph at the default size will be at the defined point size.

Usage

export_graph_start(
  file,
  pt = 10,
  width = 1,
  height,
  w2h = 1.75,
  h2w,
  sideways = FALSE,
  res = 300,
  type = NULL,
  ...
)

export_graph_end()

Arguments

file	Character scalar. The name of the file in which to save the graph. If the argument type is NULL, the type of file is deduced from the extension. If your file extension is different from your file type, you need to use the argument type.
pt	The size of the text, in pt, once the figure is inserted in your final document. The default is 10. This means that all text appearing in the plot with cex = 1 will appear with 10pt-sized fonts in your document.
width	The width of the graph, expressed in percentage of the width of the body-text of the document in which it will be inserted. Default is 1, which means that the graph will take 100% of the text width. It can also be equal to a character of the type "100%" or "80%". Alternatively, the following units are valid. Relative sizes: "pw" (page width), "tw" (text width), "ph" (page height), "th" (text height). Absolute sizes: "in", "cm", and "px".
height	Numeric between 0 and 1 or character scalar. The height of the graph, expressed in percentage of the height of the body-text of the document in which it will be inserted. Default is missing, and the height is determined by the other argument w2h. This argument should range between 0 and 1. It can also be equal to a character of the type "100%" or "80%". Alternatively, the following units are valid. Relative sizes: "pw" (page width), "tw" (text width), "ph" (page height), "th" (text height). Absolute sizes: "in", "cm", and "px".
w2h	Numeric scalar. Used to determine the height of the figure based on the width. By default it is equal to 1.75 which means that the graph will be 1.75 larger than tall. Note that when argument sideways = TRUE, the default for the height becomes ⁠90%⁠.
h2w	Numeric scalar, default is missing. Used to determine the aspectr ratio of the figure.
sideways	Logical, defaults to FALSE. If the figure will be placed in landscape in the final document, then sideways should be equal to TRUE. If TRUE, then the argument width now refers to the height of the text, and the argument height to its width.
res	Numeric, the resolution in ppi. Default is 300.
type	Character scalar, default is NULL. The type of file to be created. If NULL, the default, then the type of file is deduced from the extension.
...	Other arguments to be passed to bmp, png, jpeg, or tiff. For example: antialias, bg, etc.

Details

To export a ggplot2 graph, remember that you need to print it!

library(ggplot2)
data = data.frame(x = c(1, 2, 3, 4, 5), y = c(2, 4, 6, 8, 10))

# NOT GOOD
export_graph_start("test.pdf")
ggplot(data, aes(x, y)) +
  geom_point(color = "#54BF98") +
  geom_line(color = "#d34661")
export_graph_end()

# GOOD
my_graph = ggplot(data, aes(x, y)) +
             geom_point(color = "#54BF98") +
             geom_line(color = "#d34661")

export_graph_start("test.pdf")
print(my_graph)
export_graph_end()

When the function export_graph_end() is called, the resulting exported graph is displayed in the Viewer. The viewer function is found with getOption("viewer") and should work on RStudio and VSCode (with the R extension).

Value

These functions do not return anything in R. export_graph_start creates a file linked to the R graphics engine, in which subsequent plots are saved. export_graph_end closes the connection and the file.

Functions

• export_graph_end(): Ends the connection to the current export and creates the file.

Setting the page size

You can set the page size with the function setFplot_page, which defines the size of the page and its margins to deduce the size of the body of the text in which the figures will be inserted. By default the page is considered to be US-letter with normal margins (not too big nor thin).

It is important to set the page size appropriately to have a final plotting-text size guaranteed once the figure is inserted in the document.

Author(s)

Laurent Berge

See Also

The tool to set the page size and the exporting defaults: setFplot_page. Exporting functions pdf_fit, png_fit, jpeg_fit.

The functions export_graph_start() and export_graph_end() provide similar features.

Examples

tmpFile = file.path(tempdir(), "png_examples.pdf")

# we start the exportation
export_graph_start(tmpFile, pt = 8)

plot(1, 1, type = "n", ann = FALSE)
text(1, 1, "This text will be displayed in 8pt.")

# the line below closes the connection and displays the 
# graph in the viewer pane if appropritate
export_graph_end()

fplot documentation built on Aug. 24, 2023, 5:09 p.m.