`pi` Day 2013 Art Posters
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.
2013 was the first year in which I made `\pi` day art. It was a year of dots and love.
René Hansen has created an interactive version of this year's posters! Why not go to the Feynman point directly!
All the posters are also available without the "`\pi` day 3 · 14" inscription.
buy artwork
buy artwork
700 digits (20 x 35)
`\pi_i` / grey 80% opacity
`\pi_i`/`\pi_{i+1}` 80% opacity
2,800 (40 x 70) digits
`\pi_i` / grey 80% opacity (equal neighbours connected)
`\pi_i` / `\pi_{i+1}` 80% opacity (equal neighbours connected)
— / `\pi_{i+1}` (equal neighbours connected, unconnected digits not shown)
`\pi_i` / `\pi_{i+1}` (equal neighbours connected with line width proportional to difference in neighbour digits `d in \{0,1,2\}`, unconnected digits not shown)
`\pi_i` / `\pi_{i+1}` (equal neighbours connected with line width proportional to difference in neighbour digits `d in \{0...5\}`, unconnected digits not shown)
`\pi` : — / red (equal neighbours connected, unconnected digits not shown)
`\phi` : — / white (equal neighbours connected, unconnected digits not shown)
`e` : — / grey (equal neighbours connected, unconnected digits not shown)
11,400 (80 x 140) digits
`\pi_i` / grey 80% opacity (equal neighbours connected)
`\pi_i` / `\pi_{i+1}` 80% opacity (equal neighbours connected)
`\pi_i` / grey 80% opacity (equal neighbours connected, unconnected digits not shown)
`\pi_i` / `\pi_{i+1}` 80% opacity (equal neighbours connected, unconnected digits not shown)
love in `\pi`
Happy 2026 π Day—
Art for the 5%
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.
Ishihara's Tests for Colour Deficiency
Authentic and accurate images of Ishihara's test plates photographed (and lovingly color-corrected) from the 38-plate Ishihara's Tests for Colour Deficiency.
I also provide the position, size, and color of each circle on each test plate.
Symmetric alternatives to the ordinary least squares regression
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.
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.
Beyond Belief Campaign BRCA Art
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.
Propensity score weighting
The needs of the many outweigh the needs of the few. —Mr. Spock (Star Trek II)
This month, we explore a related and powerful technique to address bias: propensity score weighting (PSW), which applies weights to each subject instead of matching (or discarding) them.
Kurz, C.F., Krzywinski, M. & Altman, N. (2025) Points of significance: Propensity score weighting. Nat. Methods 22:638–640.
Happy 2025 π Day—
TTCAGT: a sequence of digits
Celebrate π Day (March 14th) and sequence digits like its 1999. Let's call some peaks.
