Martin Krzywinski / Genome Sciences Center / mkweb.bcgsc.ca Martin Krzywinski / Genome Sciences Center / mkweb.bcgsc.ca - contact me Martin Krzywinski / Genome Sciences Center / mkweb.bcgsc.ca on Twitter Martin Krzywinski / Genome Sciences Center / mkweb.bcgsc.ca - Lumondo Photography Martin Krzywinski / Genome Sciences Center / mkweb.bcgsc.ca - Pi Art Martin Krzywinski / Genome Sciences Center / mkweb.bcgsc.ca - Hilbertonians - Creatures on the Hilbert Curve
syncopation & accordionCafe de Flore (Doctor Rockit)like France, but no dog poopmore quotes

DNA on 10th — street art, wayfinding and font


data visualization + art

If you like space, you'll love my the 12,000 billion light-year map of clusters, superclusters and voids. Find the biggest nothings in Boötes and Eridanus.

IAU Sky Constellation Resources

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— Viorica Hrincu

Having recently drawn a few skycharts (Superclusters & Voids, Sanctuary Project), I was frustrated by the lack of parsable resources for the IAU Constellations.

Finding a plain-text parsable definition of the asterisms proved impossible. So I created my own.

IAU Constellation Shapes

DOWNLOAD CONSTELLATION SHAPE FILE

DOWNLOAD YALE CATALOGUE OF BRIGHT STARS POSITION FILE

# CHANGE LOG
# 
# 29 Nov 2018
#  + line between Betelgeuse (HR 2061) and Bellatrix (HR 1790) in Orion added
#
# 27 June 2018
#  + Greek designations now a separate field
#  + fixed Proxima Centauri and Barnard's Star, neither of which
#      are in BSC

All the constellation shapes were derived by manually examining the IAU map and cross-referencing the stars to the Yale Catalogue of Bright Stars.

The list of IAU constellation shapes in the file linked to above conveniently includes the J2000 right ascention and declination for each stars in the pair, along with their HR index, magnitude, Greek letter designation and name. See the file header for all the details.

For example, Cassiopeia's familiar "W" appears as 4 lines that indicate the connections between HR stars 21-168-264-403-542.

Cas  21  2.294583 59.149722 2.27 bet Caph|bet Cas|11 Cas	        
    168 10.127083 56.537222 2.23 alf Schedar|alf Cas|18 Cas
Cas 168 10.127083 56.537222 2.23 alf Schedar|alf Cas|18 Cas	
    264 14.177083 60.716667 2.47 gam BU 499A|BU 1028|gam Cas|27 Cas
Cas 264 14.177083 60.716667 2.47 gam BU 499A|BU 1028|gam Cas|27 Cas
    403 21.454167 60.235278 2.68 del Ruchbah|BUP 19A|del Cas|37 Cas
Cas 403 21.454167 60.235278 2.68 del Ruchbah|BUP 19A|del Cas|37 Cas
    542 28.598750 63.670000 3.38 eps Segin|eps Cas|45 Cas

The names are obtained from IAU Catalog of Star Names (IAU-CSN) and Simbad's name fields "NAME", "*" and "**", in that order. You can conveniently browse the Simbad database by any star identifier. For example, for Sirius the URL is http://simbad.u-strasbg.fr/simbad/sim-id?Ident=sirius.

Please report any errors to me.

Bitmap, SVG and PDF Constellation Shapes

The shapes of all the constellations and the stars that define the asterisms shown in the image below. I also include all the 110 Messier objects with common names in this map (hollow circles).

The map also shows the galactic equator and the ecliptic. The vernal equinox, summer solstice, autumn equinox and winter solstice occur along the ecliptic at right ascension 0/360 (Pices), 270 (Sagittarius), 180 (Vigo) and 90 (Gemini/Taurus).

Whole-sky star charts are traditionally drawn with 360 right ascention on the left in decreasing order towards 0 on the right.

Shapes of IAU Sky Constellations / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
All 88 IAU constellations and their stars. Also included are all 110 Messier objects.

You can download this file as PNG, SVG or PDF.

If you're interested in more astronomical resources, check out my Universe Superclusters and Voids resource page.

Detailed Sky Chart

I've also created detailed charts that include all the 9,110 stars in the Yale Catalogue of Bright Stars. These are labeled by their Greek designation with the constellation as well as with their IAU name.

Shapes of IAU Sky Constellations / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
A closeup of the detailed map in the region of Auriga and Perseus. The Pleiades can be seen at the bottom right.

The maps also show all 110 Messier objects, labeled by their index and, where available, a common name. All the labels in these maps have been lovingly adjusted manually to avoid ambiguity and overlap. Available are blue, black and white background versions.


 / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca buy artwork
Sky chart with all 9,110 BSC stars, 88 IAU constellations and all 110 Messier objects. Where available, objects are labled with their common name. Also shown are the galactic equator and the ecliptic. (BUY ARTWORK)

 / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca buy artwork
Sky chart with all 9,110 BSC stars, 88 IAU constellations and all 110 Messier objects. Where available, objects are labled with their common name. Also shown are the galactic equator and the ecliptic. (BUY ARTWORK)

 / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca buy artwork
Sky chart with all 9,110 BSC stars, 88 IAU constellations and all 110 Messier objects. Where available, objects are labled with their common name. Also shown are the galactic equator and the ecliptic. (BUY ARTWORK)
VIEW ALL

news + thoughts

Analyzing outliers: Robust methods to the rescue

Sat 30-03-2019
Robust regression generates more reliable estimates by detecting and downweighting outliers.

Outliers can degrade the fit of linear regression models when the estimation is performed using the ordinary least squares. The impact of outliers can be mitigated with methods that provide robust inference and greater reliability in the presence of anomalous values.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Analyzing outliers: Robust methods to the rescue. (read)

We discuss MM-estimation and show how it can be used to keep your fitting sane and reliable.

Greco, L., Luta, G., Krzywinski, M. & Altman, N. (2019) Points of significance: Analyzing outliers: Robust methods to the rescue. Nature Methods 16:275–276.

Background reading

Altman, N. & Krzywinski, M. (2016) Points of significance: Analyzing outliers: Influential or nuisance. Nature Methods 13:281–282.

Two-level factorial experiments

Fri 22-03-2019
To find which experimental factors have an effect, simultaneously examine the difference between the high and low levels of each.

Two-level factorial experiments, in which all combinations of multiple factor levels are used, efficiently estimate factor effects and detect interactions—desirable statistical qualities that can provide deep insight into a system.

They offer two benefits over the widely used one-factor-at-a-time (OFAT) experiments: efficiency and ability to detect interactions.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Two-level factorial experiments. (read)

Since the number of factor combinations can quickly increase, one approach is to model only some of the factorial effects using empirically-validated assumptions of effect sparsity and effect hierarchy. Effect sparsity tells us that in factorial experiments most of the factorial terms are likely to be unimportant. Effect hierarchy tells us that low-order terms (e.g. main effects) tend to be larger than higher-order terms (e.g. two-factor or three-factor interactions).

Smucker, B., Krzywinski, M. & Altman, N. (2019) Points of significance: Two-level factorial experiments Nature Methods 16:211–212.

Background reading

Krzywinski, M. & Altman, N. (2014) Points of significance: Designing comparative experiments.. Nature Methods 11:597–598.

Happy 2019 `\pi` Day—
Digits, internationally

Tue 12-03-2019

Celebrate `\pi` Day (March 14th) and set out on an exploration explore accents unknown (to you)!

This year is purely typographical, with something for everyone. Hundreds of digits and hundreds of languages.

A special kids' edition merges math with color and fat fonts.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
116 digits in 64 languages. (details)
Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
223 digits in 102 languages. (details)

Check out art from previous years: 2013 `\pi` Day and 2014 `\pi` Day, 2015 `\pi` Day, 2016 `\pi` Day, 2017 `\pi` Day and 2018 `\pi` Day.

Tree of Emotional Life

Sun 17-02-2019

One moment you're :) and the next you're :-.

Make sense of it all with my Tree of Emotional life—a hierarchical account of how we feel.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
A section of the Tree of Emotional Life.

Find and snap to colors in an image

Sat 29-12-2018

One of my color tools, the colorsnap application snaps colors in an image to a set of reference colors and reports their proportion.

Below is Times Square rendered using the colors of the MTA subway lines.


Colors used by the New York MTA subway lines.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Times Square in New York City.
Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Times Square in New York City rendered using colors of the MTA subway lines.
Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Granger rainbow snapped to subway lines colors from four cities. (zoom)

Take your medicine ... now

Wed 19-12-2018

Drugs could be more effective if taken when the genetic proteins they target are most active.

Design tip: rediscover CMYK primaries.

More of my American Scientific Graphic Science designs

Ruben et al. A database of tissue-specific rhythmically expressed human genes has potential applications in circadian medicine Science Translational Medicine 10 Issue 458, eaat8806.