问题
I've experienced a problem when exporting a ggvis
plot (by using vg2png).
A simple case works nicely:
library(ggvis)
mtcars %>% ggvis(x = ~hp, y = ~mpg) %>% export_png()
However, if I want to export grouped data, I get the following error:
mtcars %>% ggvis(x = ~hp, y = ~mpg) %>% group_by(cyl) %>% export_png()
/usr/local/lib/node_modules/vega/vega.js:4799
var tx = vg.data[def.type]();
^
TypeError: Property 'treefacet' of object #<Object> is not a function
at vg.parse.transform (/usr/local/lib/node_modules/vega/vega.js:4799:29)
at Array.map (native)
at Object.vg.parse.dataflow (/usr/local/lib/node_modules/vega/vega.js:4261:34)
at /usr/local/lib/node_modules/vega/vega.js:4234:27
at Array.forEach (native)
at Object.vg.parse.data (/usr/local/lib/node_modules/vega/vega.js:4223:16)
at parse (/usr/local/lib/node_modules/vega/vega.js:4788:22)
at Object.vg.parse.spec (/usr/local/lib/node_modules/vega/vega.js:4794:23)
at Object.vg.headless.render (/usr/local/lib/node_modules/vega/vega.js:7248:12)
at render (/usr/local/lib/node_modules/vega/bin/vg2png:55:15)
Could you suggest me any solution of this? This issue has bee reported here but still no solution/workaround.
Edited
The function export_png
exports a PNG
or SVG
from a ggvis object and requires that the external program vg2png
is installed. This is part of the vega
node.js
module. This information is obtained from ?export_png
.
来源:https://stackoverflow.com/questions/27674431/exporting-ggvis-plot-with-grouped-data