I am encountering problems using the png() function to save around 20 charts
to separate files.

My script is conceptually structured as follows:

### <script>
png("Image %03d.png")

# the following are calls to user-defined functions I wrote that call plot,
barchart, etc. with special arguments.
 myPlot("a")
myPlot("b")
myPlot("c")

myBarchart("a")
myBarchart("b")
myBarchart("c")

 myBarchart2("a")
myBarchart2("b")
myBarchart2("c")

dev.off()
### </script>

When I run the code a few lines at a time it generates the images correctly.
However, when I execute all lines of the script at once (Ctrl+A, Ctrl+R in
the Rgui editor), the output doesn't get generated right. Most notably:

- Only one plot created by myBarchart (or myBarchart2) gets saved, instead
of all 3
- Some images are blank

I'm having trouble isolating the problem to one line of code.

I suspect there is some fundamental paradigm I'm not aware of about how R
devices and images work, perhaps relating to the importance of the order in
which the calls to png, dev.off(), etc. are executed, the required state of
my workspace before I run the code (e.g. whether the previous plot window
should be open or closed), or maybe even time dependency (do I need to
insert timed pauses so that my diagram has time to render before saving to a
file?).

Does this ring a bell to anyone? I read the R documentation on devices and
png(), and searched the mailing list archives and the web, but haven't
figured out how to get this working. Any help would be appreciated.

Thanks,

Rex

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