[HN Gopher] Which color scale to use when visualizing data
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Which color scale to use when visualizing data
Author : ingve
Score : 62 points
Date : 2021-03-17 12:05 UTC (10 hours ago)
(HTM) web link (blog.datawrapper.de)
(TXT) w3m dump (blog.datawrapper.de)
| hprotagonist wrote:
| "NOT JET", and then according to your taste, data need, and
| accessibility concerns as required.
| stevesimmons wrote:
| I'd suggest _not_ using Google Maps ' color scheme.
|
| Try printing out one of their maps on a monochrome printer, and
| you'll see what I mean: The colour shades, grey boundaries for
| roads and natural features, and the road names all have virtually
| the same contrast. So they all print as nearly the same illegible
| light grey.
| viklove wrote:
| Probably not a consideration for the vast majority of use
| cases. Honestly, why would you ever want to print out a
| screenshot of Google Maps? I remember my parents doing it back
| in the days of MapQuest before smartphones, but I can't think
| of any reason to do something so wasteful today.
| KineticLensman wrote:
| > Honestly, why would you ever want to print out a screenshot
| of Google Maps?
|
| Agree, but stevesimmons's point still stands - Google's map
| colour scheme is not a good role model.
| stevesimmons wrote:
| I want to do it suprisingly often.
|
| * _When running /cycling somewhere unfamiliar:_ My phone will
| be safe in my backpack. In my hands I want a map I can stuff
| in a pocket, not worry if it gets wet or rained on, that I
| can hold while gripping the handlebars, that I can use while
| wearing gloves, and write other notes on, etc. I could print
| in color on my inkjet printer, but the ink runs in the rain.
| A printout from my mono laser won't run, but Google Maps
| isn't legible then either.
|
| * _On occasions when you don 't want to bring a phone_: What
| actually prompted my original comment was yesterday I had a
| government language exam, in an unfamiliar location on the
| outskirts of town, with strict instructions that no phones or
| other personal possessions were allowed in... I wasn't sure
| what kind of lockers they would have, or whether they would
| need padlocks or coins (neither of which I had) or whatever.
| So I thought about printing out a map and leaving my phone at
| home. The weather forecast was for rain, and I planned on
| cycling, hence it made sense to laser-print rather than use
| my inkjet.
| hutzlibu wrote:
| "Honestly, why would you ever want to print out a screenshot
| of Google Maps?"
|
| Long traveling/hiking.
|
| To save smartphone batterie
|
| to have something on your table, your hiking group can easier
| talk about, than by watching it on someones screen
| Gravityloss wrote:
| It has very low contrast so it's really hard to use for
| anything.
|
| You can't tell river from forest from residential area. It's
| all basically some light almost-grey.
|
| Regular street maps and topographical maps are way better.
| mhils wrote:
| Related, Claus Wilke's Data Visualization book has a fantastic
| section on common pitfalls of color use:
|
| https://clauswilke.com/dataviz/color-basics.html
| https://clauswilke.com/dataviz/color-pitfalls.html
| splittingTimes wrote:
| IBM did research back in the 90s on perceptually-based colormaps
| and how to best represent various types of data within the color
| dimensions of luminescence, saturation and hue [1]. For exampale,
| they found that,
|
| (1) Hue was not a good dimension for encoding magnitude
| information, i.e. rainbow color maps are bad.
|
| (2) The mechanisms in human vision responsible for high spatial
| frequency information processing are luminance channels. If the
| data to be represented have high spatial frequency, use a color
| map which has a strong luminance variation across the data range.
|
| (3) For interval and ratio data, both luminance- and saturation-
| varying color maps should produce the effect of having equal
| steps in data value correspond to equal perceptual steps, but the
| first will be most effective for high spatial frequency data
| variations and the second will be most effective for low spatial
| frequency variations.
|
| ===
|
| [1] https://www.research.ibm.com/people/l/lloydt/color/color.HTM
|
| or as pdf:
|
| https://github.com/frankMilde/interesting-reads/blob/master/...
| jefecoon wrote:
| Great article exploring specific colormaps and applications, incl
| discussion of pros/cons of popular maps [ e.g. Cividis better for
| color-blind viewing than Viridis, but is a more simplistic blue--
| yellow scale than others which utilize higher number of colors ]:
| https://www.kennethmoreland.com/color-advice/
|
| Great, widely-referenced site for quickly generating color
| scales, w color-blind safe options, and large amount of research
| behind it:
| https://colorbrewer2.org/#type=sequential&scheme=BuGn&n=3
| erex78 wrote:
| At Mapsense we would always refer to Color Brewer
| https://colorbrewer2.org/. Basically takes the thinking out of
| the equation.
| Cd00d wrote:
| Great resource in colorbrewer2 - thank you!
|
| I have several color blind colleagues and am regularly
| concerned I'm not displaying visuals in a way that is easy for
| them to digest.
| retrac wrote:
| Most of the advice on how to make a chart readable for the
| colourblind also helps keep it intelligible when converted to
| greyscale. Unless colour is vital to communicating something with
| a chart, I always check to make sure it's still understandable in
| greyscale. Old habit from the days of B&W laser printers and copy
| machines, but it hasn't done me wrong yet.
| java-man wrote:
| Please also consider readers with color vision deficiency: no
| information should ideally be conveyed via color alone.
| [deleted]
| stevesimmons wrote:
| Another good resource is the tutorial "Choosing Color Palettes"
| from Seaborn, a Python plotting library that extends Matplotlib:
|
| https://seaborn.pydata.org/tutorial/color_palettes.html
| dredmorbius wrote:
| For content likely to be printed, photocopied, or viewed on an
| e-Ink device (colour exists in each case, but B&W/greyscale is
| far more prevalent), a palette or design which translates well to
| monochrome may be well worth considering.
|
| Muti-generation photocopies tend toward black and white only.
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(page generated 2021-03-17 23:01 UTC)