I just discovered Hanpuku, a best-in-class solution for working with data visualization. I don't think there's anything better than this amazing piece of software!
Hanpuku Overview
Old answer
I'd like to describe a workflow using this option mentioned by user568458:
I have given up on Illustrator's bronze age tool for doing charts of poll answers (mostly bar/column graphs, pie charts and line plots). Illustrator couldn't handle corrections, small tweaks or updated data - any modification ruined the layout. I also couldn't specify key dimensions that had to stay constant throughout the set of charts (bar height, font size, max height).
Check out JSGraphs.com, tons of JavaScript graphing frameworks are compared there, and you can pick the most suitable one for your project.
I also used python livereload to live code (auto-refresh on save, actually). It gets things moving along faster! Navigate to the project folder in command prompt / terminal and just type livereload
. All project files are now served and can be accessed on URLs like http://localhost:35729/chart-01.html
.
It takes an up-front investment of time to learn the charting framework, its quirks and limitations, but once your first few charts are built you can use them as templates, sometimes just plugging in new data, changing nothing else.
My framework would accept CSV files as input, which I got by exporting from .xlsx files. Plugging in new data was done by changing one line of code url: 'resources/graph-02.csv'
Color themes could also be managed similarly with a JSON file.
From here on up to delivering CMYK EPSes much of the workflow can be automated.
Depending on the framework, exporting to SVG can be as easy as CtrlS. If it's embedded in the HTML markup as an SVG element you can batch export it with Playfair.
justinmanley/playfair: Generate charts and graphs from the command line using d3 and PhantomJS..
Initially I just used UI automation tools that would replicate enter-URL-save-as-enter-next-URL-save-as monkey-work for each file in the folder - AutoHotkey or WASP for PowerShell.
To batch convert SVGs to CMYK EPS files I made an action in Illustrator.