Big updates: Better layout, new controls

3 small example diagrams showing some of the new output capabilities of SankeyMATIC. The first example is a funnel where the initial nodes lose value and converge on a single final node. The second is an image where one node splits into two child flows; the top child node splits into two more child flows; then the top grandchild splits into two more flows. The third is a binary tree showing 8 elements collapsing down to one and then splitting into 8 nodes again on the far end. Each type of image will be referenced below.

Adapted from a Mastodon thread.

Friends: I have been spending time in the Land of Somewhat Challenging Geometry Algorithms.

After an extended stay there, I return to you with some visible improvements to share.

Improvement #1: A better layout engine!

SankeyMATIC has new ideas about how to arrange Nodes and Flows.

It now puts more effort into producing more balanced, more symmetrical, less lopsided diagrams.

Below are a couple of examples showing the difference it can make.

(To make comparisons clear, the same data inputs were used for the Old vs. New versions.)

2 pairs of before & after images demonstrating the improved SankeyMATIC layout algorithm. Each pair shows a lopsided image 'before' and a much more symmetrical one 'after' given the same inputs as the first image. At the bottom is the text: Same input data + better layouts = (tada emoji)

One specific improvement these changes make possible:

Tree diagrams which are symmetrical!

You see tree patterns in lots of places, including sports tournament brackets.

Despite their simple structure, SankeyMATIC was not handling them well before.

It’s much better now:

2 pairs of before & after images showing the new algorithm's symmetrical output for simple tree diagrams. The first pair show a single node splitting in half to become 2 children and then 4 grandchildren. The 'after' image has a horizontal dotted line to indicate the axis of symmetry. The second pair of images shows 8 nodes flowing into 4, then 2, then 1, then the reverse (2 then 4 then 8). The 'after' image contains a vertical and horizontal dotted line pointing out the dual axes of symmetry. At the bottom is the text: Symmetry!

When your data has any other internal symmetry, the diagram ought to reflect that when it can.

Now, Flows from Nodes which don’t have their full value flowing in/out can attach to the bottom of a Node when that makes sense.

This usually makes such diagrams look better, e.g. in the case of a funnel pattern:

2 pairs of before & after images showing off the new SankeyMATIC layout algorithm. The first pair shows nodes losing value as they proceed through stages; eventually they converge on a single final node. The second pair shows a single node feeding into 2 nodes which gain value from nowhere and eventually converge back to one node; the effect is to produce a diamond-shaped diagram. At the bottom is the text: Better 'unbalanced' diagrams, including funnels.'

Improvement #2: More precise controls

The “Spacing” slider for Nodes has split into two: “Height” & “Spacing“.

Comparison of the old and new Node UI control panel for SankeyMATIC. In the old version, there is a Spacing slider highlighted, which spans the range '0' to 'Max'. In the new version, the Spacing slider looks similar (though smaller) and a new Height slider precedes it, with its range labeled as '.' to '|' (a visual cue that the beginning of the range corresponds to the least height and the end to the most).

Before, the slider was controlling both height & spacing, which wasn’t flexible.

Splitting them up gives you many more possibilities for how your diagrams look (as seen in the example images above).

In summary:

  1. Better-looking layouts!
  2. More precise visual controls!

Try out the changes! In particular, play with the Height & Spacing sliders to see how they interact.

P.S. The code behind these improvements is already posted to github.com/nowthis/sankeymatic. The commits from October 2 – November 3, 2022 contain the key changes.

P.P.S. Enormous thanks to everyone who has donated in the past; your interest and generosity help to motivate work on improvements such as these. 🙂