jsGraphic2Image: Save interactive JavaScript web graphics generated by HTML...

Description Usage Arguments Details Value Note Author(s) See Also Examples

Description

JavaScript (JS) data visualization libraries are made accessible in R by packages that are often based on the htmlwidgets package (http://www.htmlwidgets.org). These two functions, jsGraphic2Pdf and jsGraphic2Png, store such interactive web visualizations generated by JavaScript code as a PDF or PNG file. Whereas normally JavaScript visualizations are saved as standalone web pages, having PDF or PNG files means that these plots can easily be used as figures in other documents. With these two functions the conversion of web visualizations to static graphics can be easily automated, however, plots are stored in their default layout, i.e. they cannot be manipulated by the user (for this see also svgFromHtml).

Usage

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jsGraphic2Pdf(graphic, plotDims = c(1000, 500, 20, 20),
  outFile = "JSgraphic.pdf", pathPhantomJS = NULL, slow = FALSE,
  highRes = TRUE)

jsGraphic2Png(graphic, plotDims = c(1000, 500, 20, 20),
  outFile = "JSgraphic.png", pathPhantomJS = NULL, slow = FALSE,
  highRes = TRUE)

Arguments

graphic

either a plot object (e.g. typeof(graphic c("list", "S4"))) generated by a JS visualization function or a character string denoting the path to the html file that contains the JS code to generate the graphic that should be stored as an image file. Such a html file can be generated with htmlwidgets::saveWidget.

plotDims

numeric vector specifying c(width, height, margin left/right, margin top/bottom)

outFile

character string denoting the title of the output file

pathPhantomJS

character string denoting the path to the PhantomJS binary. It is assumed that PhantomJS is on the $PATH, e.g. "/usr/local/bin/phantomjs", which corresponds to the default value NULL.

slow

logical indicating that PhantomJS uses more time for rendering the visualization and rasterizing it (2500 ms vs. 200 ms). Defaults to FALSE (i.e. faster rendering).

highRes

logical indicating whether plots are rasterized in high resolution

Details

The PDF / PNG file is saved using PhantomJS (http://phantomjs.org) and the JavaScript code available at https://github.com/ariya/phantomjs/blob/master/examples/rasterize.js

Value

Returns nothing, but as a side effect saves the interactive JavaScript visualization as either a .pdf or .png file.

Note

Currently, PhantomJS crashes sometimes in case graphics were produced with Plotly.

Author(s)

Christoph Schmidt <[email protected]>

See Also

svgFromHtml, plot_crop

Examples

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#####
# already rendered JavaScript visualization saved as web page complete with
# embedded svg image (alluvial/Sankey diagram)
#####

path1 <- system.file("extdata/alplots2_ff.html", package = "js2graphic")
file.copy(path1, getwd())
file  <- "alplots2_ff.html"

jsGraphic2Pdf(file, c(950, 500, 40, 20))
pdfcrop("JSgraphic.pdf")

jsGraphic2Pdf(file, c(950, 500, 40, 20), highRes = FALSE)
pdfcrop("JSgraphic.pdf")

jsGraphic2Png(file, c(950, 500, 40, 20))
imagecrop("JSgraphic.png")

jsGraphic2Png(file, c(950, 500, 40, 20), highRes = FALSE)
imagecrop("JSgraphic.png")

file.remove(c(file, "JSgraphic.pdf", "JSgraphic_cr.pdf",
            "JSgraphic.png", "JSgraphic_cr.png"))



#####
# html saved with htmlwidgets::saveWidget() that contains JavaScript code
# to generate an interactive visualization (alluvial/Sankey diagram);
# the html file does not contain the svg file
#####

path2 <- system.file("extdata/alluvial_js.html", package = "js2graphic")
file.copy(path2, getwd())
file  <- "alluvial_js.html"
jsGraphic2Pdf(file, c(1000, 500, 40, 20))
pdfcrop("JSgraphic.pdf")

jsGraphic2Png(file, c(1000, 500, 40, 20))
imagecrop("JSgraphic.png")

file.remove(c(file, "JSgraphic.pdf", "JSgraphic_cr.pdf",
            "JSgraphic.png", "JSgraphic_cr.png"))



#####
# using a generated graphic/plot object directly
# (social network) https://christophergandrud.github.io/networkD3/
#####

library(networkD3)
data(MisLinks)
data(MisNodes)
p <- forceNetwork(Links = MisLinks, Nodes = MisNodes,
             Source = "source", Target = "target",
             Value = "value", NodeID = "name",
             Group = "group", opacity = 0.9,
             height = 900, width = 900)

# short rendering time: plot has not fully 'unfolded'
jsGraphic2Pdf(p, c(900, 900, 20, 20), slow = FALSE)
jsGraphic2Png(p, c(900, 900, 20, 20), slow = FALSE)

# longer rendering time: rendering has finished
jsGraphic2Pdf(p, c(900, 900, 20, 20), slow = TRUE)
pdfcrop("JSgraphic.pdf")

jsGraphic2Png(p, c(900, 900, 20, 20), slow = TRUE)
imagecrop("JSgraphic.png")

file.remove(c("JSgraphic.pdf", "JSgraphic_cr.pdf",
            "JSgraphic.png", "JSgraphic_cr.png"))



#####
# using a generated graphic/plot object directly
# (heatmap)
#####

library(d3heatmap)
p <- d3heatmap(mtcars, scale = "column", colors = "Blues")
jsGraphic2Pdf(p, c(2500, 2000, 50, 50))
# removing the last 2 empty pages from JSgraphic.pdf
pdfPageExtract("JSgraphic.pdf", 1, 1, "JSgraphic2.pdf")
# cropping with adding a little extra white margin to the automatic crop
pdfcrop("JSgraphic2.pdf", "JSgraphic3.pdf", c(-30, -30, -70, -30))
# JSgraphic3.pdf contains the final cropped figure

file.remove("JSgraphic.pdf", "JSgraphic2.pdf", "JSgraphic3.pdf")



#####
# using a generated graphic/plot object directly
# plotly example 1
#####

library(plotly)
p <- plot_ly(data=iris, x=~Sepal.Length, y=~Petal.Length, type="scatter", mode="markers")
jsGraphic2Pdf(p, c(1200, 1200, 0, 0), slow = FALSE)
# removing the last 2 empty pages from JSgraphic.pdf
pdfPageExtract("JSgraphic.pdf", 1, 1, "JSgraphic2.pdf")

file.remove("JSgraphic.pdf", "JSgraphic2.pdf")



#####
# using a generated graphic/plot object directly
# plotly example 2
#####
library(plotly)

trace_0 <- rnorm(100, mean = 5)
trace_1 <- rnorm(100, mean = 0)
trace_2 <- rnorm(100, mean = -5)
x <- c(1:100)

data <- data.frame(x, trace_0, trace_1, trace_2)

p <- plot_ly(data, x = ~x, y = ~trace_0, name = 'trace 0', type = 'scatter', mode = 'lines') %>%
  add_trace(y = ~trace_1, name = 'trace 1', mode = 'lines+markers') %>%
  add_trace(y = ~trace_2, name = 'trace 2', mode = 'markers')

jsGraphic2Pdf(p, c(1200, 1200, 0, 0), slow = FALSE)
# removing the last 2 empty pages from JSgraphic.pdf
pdfPageExtract("JSgraphic.pdf", 1, 1, "JSgraphic2.pdf")
file.remove("JSgraphic.pdf", "JSgraphic2.pdf")

schmidtchristoph/js2graphic documentation built on July 8, 2018, 4:10 p.m.