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Here we are now at the middle of the fourth large part of this talk.Pepe Deluxeget nowheremore quotes


EMBO Practical Course: Bioinformatics and Genome Analysis, 5–17 June 2017.


Fonts + Design

Snellen Optotype Font with Upper and Lowercase characters

In the process of designing my Snellen Eye Chart typographical posters, I came across the Snellen font by Andrew Howlett. I wasn't happy with all the letters, so I made attempts at giving the font an update.

Not being a font designer, I will likely get myself into trouble.

snellen chart posters

While making my Snellen chart series, I entered the rabbit hole of optotype fonts ... and I can't get out!


Typographical posters of how the world works in the style of Snellen eye charts
 / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca buy artwork
A technically accurate Snellen chart using four genetic bases A T G C rendered as optotypes. The chart begins with the start codon ATG and ends in the stop codon TGA, which appears only once in the chart. Print at 16 in × 24 in. (BUY ARTWORK)

Typographical posters of how the world works in the style of Snellen eye charts
 / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca buy artwork
A technically accurate Snellen chart using the nautical flag alphabet rendered as optotypes. Print at 16 in × 24 in. (BUY ARTWORK)

The charts don't necessarily use the latest version of my Snellen font design, which fluctuates as my mood about some of the letters changes.

optotype fonts

The optotype requirement is that letters be designed on a 5 × 5 grid, and have constant stroke width. This means that both lower and upper case letters need to share the grid and stroke. To stay compatible with the eyechart paradigm, letters should be as obvious as possible.

Lorrie Frear's article What are Optotypes? Eye Charts in Focus is a great read about optotypes and eye charts.

Snellen Optotype Letter Design

uppercase

The uppercase letter design uses Herman Snellen's original chart as inspiration.

I have modified the design by Andrew Howlett (see below) for some letters. All the changes are relatively minor: more serifs and consistent stroke width for bars on R and K.

lowercase

The lowercase characters should be considered experimental.

The progress of my redesign is shown below. I would greatly appreciate feedback and suggestions!

Download Snellen Optotype Font

The distribution contains both Andrew's version and my redesign.

v7.0 6-mar-2017 — Download Snellen optotype font

version 7 — 6 Feb 2017

Fixed g and e. Thanks to Makeesha Fisher for suggestions.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.7). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters as well as digits and symbols. (zoom, download Snellen optotype font)

version 6 — 5 Feb 2017

Adjusted serifs on f, j, l, o, t to extend the full width of the grid. Added a lot more symbols.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.6). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters as well as digits and symbols. (zoom, download Snellen optotype font)

version 5 — 4 Feb 2017

Added lowercase, digits and symbols.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.5). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters as well as digits and symbols. (zoom, download Snellen optotype font)

version 4 — 23 Feb 2017

Adding digits.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.4). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters as well as digits. (zoom)

version 3 — 22 Feb 2017

I'm exploring the lowercase characters. I don't know what I want to do with them. Make this into a more standard font in which lowercase letters are smaller, so that letters can fit their roles clearly when text is set in sentence case, or fill out the full optotype grid.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.3). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters. (zoom)

version 2 — 22 Feb 2017

Flushed out some inconsistencies in the uppercase characters. Added serifs to more letters.

Now all the letters occuppy the full 5 × 5 grid, including the I, whose serifs were widened to allow this. While this new uppercase I isn't as pretty as the old one, it makes the entire typeface more consistent to its optotype roots.

Still struggling with the G. In the original version, the descending stroke was cut off in the middle of a grid, which I didn't like.

The S has been fixed—thanks to Elanor Lutz for feedback.

I've color coded the characters slightly differently, drawing attention to ones that I feel need more thought.

The lowercase characters aren't color coded (yet) because ... most of them need help. Primarily, I'm vacillating between making them fill the full size of the 5 × 5 square, just like the uppercase characters, and keeping them confined to a 4 × 4 square, which incurs loss of legibility. If I make the letters the same size, it will be impossible to distinguish lowercase and uppercase characters some cases (e.g. c, i). Perhaps this is desired?

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.2). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters. (zoom)

version 1 — 22 Feb 2017

First attempt at lowercase characters.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Snellen optotype font (mk.v.1). Original design by Andrew Howlett (left) and my redesign (right), which includes both upper and lowercase letters. (zoom, download font)
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news + thoughts

Snowflake simulation

Tue 14-11-2017
Symmetric, beautiful and unique.

Just in time for the season, I've simulated a snow-pile of snowflakes based on the Gravner-Griffeath model.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
A few of the beautiful snowflakes generated by the Gravner-Griffeath model. (explore)

Gravner, J. & Griffeath, D. (2007) Modeling Snow Crystal Growth II: A mesoscopic lattice map with plausible dynamics.

Genes that make us sick

Thu 02-11-2017
Where disease hides in the genome.

My illustration of the location of genes in the human genome that are implicated in disease appears in The Objects that Power the Global Economy, a book by Quartz.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
The location of genes implicated in disease in the human genome, shown here as a spiral. (more...)

Ensemble methods: Bagging and random forests

Mon 16-10-2017
Many heads are better than one.

We introduce two common ensemble methods: bagging and random forests. Both of these methods repeat a statistical analysis on a bootstrap sample to improve the accuracy of the predictor. Our column shows these methods as applied to Classification and Regression Trees.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Ensemble methods: Bagging and random forests. (read)

For example, we can sample the space of values more finely when using bagging with regression trees because each sample has potentially different boundaries at which the tree splits.

Random forests generate a large number of trees by not only generating bootstrap samples but also randomly choosing which predictor variables are considered at each split in the tree.

Krzywinski, M. & Altman, N. (2017) Points of Significance: Ensemble methods: bagging and random forests. Nature Methods 14:933–934.

Background reading

Krzywinski, M. & Altman, N. (2017) Points of Significance: Classification and regression trees. Nature Methods 14:757–758.

...more about the Points of Significance column

Classification and regression trees

Mon 16-10-2017
Decision trees are a powerful but simple prediction method.

Decision trees classify data by splitting it along the predictor axes into partitions with homogeneous values of the dependent variable. Unlike logistic or linear regression, CART does not develop a prediction equation. Instead, data are predicted by a series of binary decisions based on the boundaries of the splits. Decision trees are very effective and the resulting rules are readily interpreted.

Trees can be built using different metrics that measure how well the splits divide up the data classes: Gini index, entropy or misclassification error.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Classification and decision trees. (read)

When the predictor variable is quantitative and not categorical, regression trees are used. Here, the data are still split but now the predictor variable is estimated by the average within the split boundaries. Tree growth can be controlled using the complexity parameter, a measure of the relative improvement of each new split.

Individual trees can be very sensitive to minor changes in the data and even better prediction can be achieved by exploiting this variability. Using ensemble methods, we can grow multiple trees from the same data.

Krzywinski, M. & Altman, N. (2017) Points of Significance: Classification and regression trees. Nature Methods 14:757–758.

Background reading

Lever, J., Krzywinski, M. & Altman, N. (2016) Points of Significance: Logistic regression. Nature Methods 13:541-542.

Altman, N. & Krzywinski, M. (2015) Points of Significance: Multiple Linear Regression Nature Methods 12:1103-1104.

Lever, J., Krzywinski, M. & Altman, N. (2016) Points of Significance: Classifier evaluation. Nature Methods 13:603-604.

Lever, J., Krzywinski, M. & Altman, N. (2016) Points of Significance: Model Selection and Overfitting. Nature Methods 13:703-704.

Lever, J., Krzywinski, M. & Altman, N. (2016) Points of Significance: Regularization. Nature Methods 13:803-804.

...more about the Points of Significance column

Personal Oncogenomics Program 5 Year Anniversary Art

Wed 26-07-2017

The artwork was created in collaboration with my colleagues at the Genome Sciences Center to celebrate the 5 year anniversary of the Personalized Oncogenomics Program (POG).

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
5 Years of Personalized Oncogenomics Program at Canada's Michael Smith Genome Sciences Centre. The poster shows 545 cancer cases. (left) Cases ordered chronologically by case number. (right) Cases grouped by diagnosis (tissue type) and then by similarity within group.

The Personal Oncogenomics Program (POG) is a collaborative research study including many BC Cancer Agency oncologists, pathologists and other clinicians along with Canada's Michael Smith Genome Sciences Centre with support from BC Cancer Foundation.

The aim of the program is to sequence, analyze and compare the genome of each patient's cancer—the entire DNA and RNA inside tumor cells— in order to understand what is enabling it to identify less toxic and more effective treatment options.