[CentralOH] Python Graph Help

Fri Mar 2 01:50:01 EST 2018

Sorry just noticed I said LPS when I meant LPI or PPI ...
https://forums.adobe.com/thread/370714 or
https://en.wikipedia.org/wiki/Pixel_density or
https://en.wikipedia.org/wiki/Retina_Display

On Fri, Mar 2, 2018 at 1:46 AM, Thomas Winningham <winningham at gmail.com>
wrote:

> I have some thoughts just finishing a charting task at work with D3 after
> munging a lot of data with Python and making .json files to drive it.
>
> I think you're going to have to bite the bullet and do this from scratch
> unless you can find some kind of other packaged visualization that is to
> your liking that isn't quite exactly this from some high level charting
> program out there like Bokeh, matplotlib, etc. You're going to be in the
> world of drawing rectangles, polygons, and cursing the world of
> typesetting. I'd specifically watch out for something like Plotly as they
> are sort of unethical in my opinion by making their open source products
> tie in heavily with their online product offerings. The latest notebook
> style thing from the D3 people is sort of in this SaaS lock-in realm too,
> IMHO.
>
> --- 1. What is your target? Print? Web? Static or Animated?
>
> For print I'd recommend things like tikz or R's ggplot ... and I'd also
> recommend a format like postscript / pdf or svg. Of course animations are
> out unless you're making a flip book, or rasterizing your SVGs or something
> into JPGs and then encoding with ffmpeg.
>
> For web, I'd recommend D3. It has a nifty data binding concept that is
> slick if not exactly well thought out from a traditional JS developer
> viewpoint, and a whole lot of neat things that make interpolation and such
> easier.
>
> For video, I'd recommend any of the above or even things like Processing,
> GL Shaders, Blender, moviepy, or a game framework, or a compositing tool.
>
> --- 2. Planning
>
> Looking at the sample graph there's a lot of things that I'm sure you can
> find in Python a way to come up with:
> - Triangle shape and location
> - Main bar location
> - Dividing the bar up into red / green areas
> - Scale
> - Tick marks
> - Labeling of axis
> - Text placement
>
> Text is probably the hardest. HTML has a lot of nice wrapping,
> justification, etc and SVG does not (natively) and neither do a lot of
> other things. LaTeX is of course the "best" if you have postscript / pdf in
> the mix and what really nifty things like automatic typographic ligatures
> like where like the TH pairs are done as a single glyph. Or math formula
> rendering, although MathJax will do that on the web for ya.
>
> --- 3. Transforms
>
> Things like Processing like to drive home the idea of transforms. In
> short, you begin in space at 0,0 for 2D or 0,0,0 for 3D ... some start at
> bottom left, some at top left. You have your area like width x height x
> depth, plus perhaps some concept of resolution in a raster context. For
> print 600 or 1200 or whatever is nice DPI but screen is usually 90, but in
> the mobile world these days it is all LPS and here be dragons.
>
> If you always do everything from 0,0 or center things around 0,0 then you
> can "transform" the whole block of stuff to whatever location in arbitrary
> groups. For SVG this is the "g" object... in Processing these are the
> "pushMatrix" and "translate".
>
> In 3d, 0,0,0 is "world center" usually, and in print and computer screen,
> 0,0 is again like top left usually, although I think Inkscape is bottom
> left.
>
> --- 4. Interpolation
>
> You could manually place everything in X,Y coordinates but let's take the
> tick marks for instance... you really are creating interpolation functions
> for all of these things so the Y of the tick marks is something like in
> python like range(0,100,10) for a tick mark every 10 steps.
>
> You may consider the "width" and "height" as constants and always be doing
> things in relation to those such as center being width/2 and height/2 or
> the rule of thirds /3 ...
>
> Of course all of those things can be thought of in an object oriented way
> if each thing is only concerned about its local 0,0 when doing stuff
> specifically to its function's task, and then you can assemble all those
> functions by translating them to their relative locations within the
> greater document canvas.
>
> --- 5. Python tips
>
> I've used PySVG... I also looked at "svgwrite" just now and it seems
> pretty good. For rather I've done a lot with pycairo ...
>
> SVG is just XML so you could also just sort of string concatenate your way
> to success.
>
> Another thought would be to mock up what you want with Inkscape, and use
> its "simple svg" output format to create a template you can then manipulate
> with ElementTree.
>
> For D3 everything works better IMHO with a nice JSON object to throw at
> it. Doing a lot of calculation of coordinates in Python of various data
> points where you're more comfortable, and then hacking up some basic
> examples of the drawing features of D3 was a template I used with this last
> project.
>
> .......
>
> So, best of luck, that's about it for some random ramblings on the
> subject. In short, If this is for a website and animated, maybe using
> PyCairo stills into FFMPEG to make GIFs or use D3 and use SVG and
> JavaScript. In just for the website and static, use PySVG, svgwrite, or
> pycairo.
>
> If you can find something that will get the point across, it will save a
> lot of time "drawing" everything to just throw your data at a packaged
> visualization tool.
>
> Best of luck,
>
> Thomas
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> On Thu, Mar 1, 2018 at 10:45 PM, mrehner <mrehner at e-wrench.net> wrote:
>
>> Eric,
>>
>>
>>
>> Can't really help on the implementation level. It looks like what you
>> have is a 'box plot' or a 'facet grid'.  You can add the triangle with an
>> 'annotation', probably as a subplot. Seaborn has al built in function
>> 'factorplot' that supposedly simplifies making these kind of plots.
>> Unfortunately I don't have any experience in making these kind of plots,
>>  only  a book in which I'm trying to learn about data analytics. All I have
>> may be some techincal terms that may or may not help your search.
>>
>>
>>
>> Cheers,
>>
>>
>>
>> Mike
>>
>>
>>
>> *From:* CentralOH [mailto:centraloh-bounces+mrehner=
>> e-wrench.net at python.org] *On Behalf Of *Eric Floehr
>> *Sent:* Thursday, March 1, 2018 5:45 PM
>> *To:* Central Ohio Python Users Group
>> *Subject:* [CentralOH] Python Graph Help
>>
>>
>>
>> All,
>>
>>
>>
>> I'm trying to determine which python graphing library would be able to
>> make the following graph type. I don't have a name for it, but here is the
>> description...
>>
>>
>>
>> It's basically a vertical or horizontal line on some scale, with shaded
>> rectangles over parts of it indicating certain things, and a triangle with
>> a specific number pointing to that spot on the line.
>>
>>
>>
>> The closest example is the original Star Trek sick bay charts, and I
>> found an example here:
>>
>>
>>
>> https://blogs.sas.com/content/sastraining/files/2017/06/star
>> trek_med_dashboard_tips.gif
>>
>>
>>
>> Any thoughts?
>>
>>
>> Thanks so much!
>>
>> Eric
>>
>>
>>
>> _______________________________________________
>> CentralOH mailing list
>> CentralOH at python.org
>> https://mail.python.org/mailman/listinfo/centraloh
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/centraloh/attachments/20180302/db82a113/attachment.html>