visualization
+ math
▲ 2026 π DAY | Art for the 5%. Digits of `\pi` hidden in plain view.
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explore the art)
▲ 2026 π DAY | Art for the 5%. Digits of `\pi` hidden in plain view.
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explore the art)
π Day 2025 Art Posters - TTCAGT: a sequence of digits
▲ 2026 π DAY | Art for the 5%.
▲ 2025 π DAY | TTCAGT: A sequence of digits.
▲ 2024 π DAY | Explore the garden of digits.
▲ 2023 π DAY | Repeated sequence
▲ 2022 π DAY | three one four: a number of digits
▲ 2021 π DAY | Good things grow for those who wait.' edition.
▲ 2020 π DAY | The piku.
▲ 2019 π DAY | Hundreds of digits, hundreds of languages and a special kids' edition.
▲ 2018 π DAY | Street maps to new destinations.
▲ 2017 π DAY | Imagine the sky in a new way.
▲ 2016 π APPROXIMATION DAY | What would happen if about right was right.
▲ 2016 π DAY | These digits really fall for each other.
▲ 2015 π DAY | A transcendental experience.
▲ 2014 π APPROXIMATION DAY | Spirals into roughness.
▲ 2014 π DAY | Hypnotizes you into looking.
▲ 2014 π DAY | Come into the fold.
▲ 2013 π DAY | Where it started.
▲ CIRCULAR π ART | And other distractions.
On March 14th celebrate `\pi` Day. Hug `\pi`—find a way to do it.
For those who favour `\tau=2\pi` will have to postpone celebrations until July 26th. That's what you get for thinking that `\pi` is wrong. I sympathize with this position and have `\tau` day art too!
If you're not into details, you may opt to party on July 22nd, which is `\pi` approximation day (`\pi` ≈ 22/7). It's 20% more accurate that the official `\pi` day!
Finally, if you believe that `\pi = 3`, you should read why `\pi` is not equal to 3.
Well—well; the sad minutes are moving,
Though loaded with trouble and pain;
And some time the loved and the loving
Shall meet on the mountains again!
—Emily Bronte
Welcome to this year's celebration of `\pi` and mathematics.
The theme this year is Sanger sequencing — old-school, one base at a time.
This year's `\pi` poem is Loud Without The Wind Was Roaring by Emily Bronte.
This year's `\pi` day song is Movements by Luca Musto.
Also, the tabbed menu above is full. Gasp.
▲ TTACGT: A SEQUENCE OF DIGITS | This year, `\pi` is encoded into a sequence of nucleotides, shown as peaks that appear during Sanger sequencing.
three one four: a number of notes
·
The 2022 π Day art is a music album composed by
Greg Coles for solo piano. It tells stories from the very beginning (314…) to the very (known) end of π (…264) as well as math (Wallis Product) and math jokes (Feynman Point), repetition (nn) and zeroes (null).
This year's sequence of digits reflects on a number of notes from 2022.
Go roaring.
Loud Without The Wind Was Roaring
Loud without the wind was roaring
Through th'autumnal sky;
Drenching wet, the cold rain pouring,
Spoke of winter nigh.
All too like that dreary eve,
Did my exiled spirit grieve.
Grieved at first, but grieved not long,
Sweet—how softly sweet!—it came;
Wild words of an ancient song,
Undefined, without a name.
“It was spring, and the skylark was singing:”
Those words they awakened a spell;
They unlocked a deep fountain, whose springing,
Nor absence, nor distance can quell.
In the gloom of a cloudy November
They uttered the music of May ;
They kindled the perishing ember
Into fervour that could not decay.
Awaken, o'er all my dear moorland,
West-wind, in thy glory and pride!
Oh! call me from valley and lowland,
To walk by the hill-torrent's side!
It is swelled with the first snowy weather;
The rocks they are icy and hoar,
And sullenly waves the long heather,
And the fern leaves are sunny no more.
There are no yellow stars on the mountain
The bluebells have long died away
From the brink of the moss-bedded fountain—
From the side of the wintry brae.
But lovelier than corn-fields all waving
In emerald, and vermeil, and gold,
Are the heights where the north-wind is raving,
And the crags where I wandered of old.
It was morning: the bright sun was beaming;
How sweetly it brought back to me
The time when nor labour nor dreaming
Broke the sleep of the happy and free!
But blithely we rose as the dawn-heaven
Was melting to amber and blue,
And swift were the wings to our feet given,
As we traversed the meadows of dew.
For the moors! For the moors, where the short grass
Like velvet beneath us should lie!
For the moors! For the moors, where each high pass
Rose sunny against the clear sky!
For the moors, where the linnet was trilling
Its song on the old granite stone;
Where the lark, the wild sky-lark, was filling
Every breast with delight like its own!
What language can utter the feeling
Which rose, when in exile afar,
On the brow of a lonely hill kneeling,
I saw the brown heath growing there?
It was scattered and stunted, and told me
That soon even that would be gone:
It whispered, “The grim walls enfold me,
I have bloomed in my last summer's sun.”
But not the loved music, whose waking
Makes the soul of the Swiss die away,
Has a spell more adored and heartbreaking
Than, for me, in that blighted heath lay.
The spirit which bent 'neath its power,
How it longed—how it burned to be free!
If I could have wept in that hour,
Those tears had been heaven to me.
Well—well; the sad minutes are moving,
Though loaded with trouble and pain;
And some time the loved and the loving
Shall meet on the mountains again!
—Emily Bronte
news
+ thoughts
Mon 04-05-2026
It is not certain that everything is uncertain. —Blaise Pascal
We have already explored how we can mitigate bias caused by confounding variables in observational studies using propensity score (PS) matching (PSM) and propensity score weighting (PSW). However, any statistical model is only as good as its assumptions and, if it is specified incorrectly, it can itself produce biased estimates of the treatment effect.
▲ Nature Methods Points of Significance column: Double Robustness.
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read)
This month, we explore double robustness, a powerful statistical concept that provides a valuable “safety net” against the risk of an incorrect model. It offers two opportunities, instead of just one, to obtain a valid estimate of the treatment effect — making it possible to draw credible causal inferences from observational data without having to depend on a single set of modeling assumptions.
Kurz, C.F., Krzywinski, M. & Altman, N. (2026) Points of significance: Double Robustness. Nat. Methods 23:868–869.
Thu 23-04-2026
My cover design on the 7 April 2026 Nature Biotechnology issue shows the dendrogram that represents a cluster of uniquely expressed (or downregulated) genes in human naive stem cells induced from such cells. Within each dendrogram block, the genomic barcode sequence (sampled from Supplementary Table 1) is depicted with a Code 39 barcode. The highlighted barcode is one of those used for cell isolation.
Ishiguro S. et al. A multi-kingdom genetic barcoding system for precise clone isolation (2026) Nature Biotechnology 44:616–629.
▲ My Nature Biotechnology phylogenetic tree cover (volume 44, issue 4, 7 April 2026).
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more)
Browse my gallery of cover designs.
▲ A catalogue of my journal and magazine cover designs.
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more)
Fri 13-03-2026
Celebrate π Day (March 14th) and enjoy the art — but only if you're part of the 5%.
Go ahead, see what you can't see.
▲ 2026 π DAY | Art for the 5%. Shown in the style of Ishihara color test plates, the art is visible only to those with colour blindness.
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details)
Wed 23-07-2025
What immortal hand or eye, could frame thy fearful symmetry? — William Blake, "The Tyger"
This month, we look at symmetric regression, which, unlike simple linear regression, it is reversible — remaining unaltered when the variables are swapped.
Simple linear regression can summarize the linear relationship between two variables `X` and `Y` — for example, when `Y` is considered the response (dependent) and `X` the predictor (independent) variable.
However, there are times when we are not interested (or able) to distinguish between dependent and independent variables — either because they have the same importance or the same role. This is where symmetric regression can help.
▲ Nature Methods Points of Significance column: Symmetric alternatives to the ordinary least squares regression. Geometry of quantities minimized in OLS and symmetric regression. OLS minimizes `\Sigma e_y^2` in `Y` ~ `X` and `\Sigma e_x^2` `X` ~ `Y`. Pythagorean regression minimizes AB (magenta). Geometric means regression (GMR) minimizes area of ABP (orange). Orthogonal regression (OR) minimizes HP (blue).
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read)
Luca Greco, George Luta, Martin Krzywinski & Naomi Altman (2025) Points of significance: Symmetric alternatives to the ordinary least squares regression. Nat. Methods 22:1610–1612.
Wed 11-06-2025
Fuelled by philanthropy, findings into the workings of BRCA1 and BRCA2 genes have led to groundbreaking research and lifesaving innovations to care for families facing cancer.
This set of 100 one-of-a-kind prints explore the structure of these genes. Each artwork is unique — if you put them all together, you get the full sequence of the BRCA1 and BRCA2 proteins.