Curiosities · Foundation · 11 min

Moving things efficiently

Optimal transport moves the right amount of mass while minimizing total cost.

WHAT HAPPENS IF…For p=0.75 and q=0.25, what is the minimum cost?
Interactive exploration
Loading the mathematical model…

Connect the picture to the ideaW1=1+2max⁡(0,p−q)W_1=1+2\max(0,p-q)

Sources place masses p and 1−p at 0 and 2; targets place q and 1−q at 1 and 3. Ordered matching sends the leftmost remaining mass to the leftmost unmet target. When p>q, the excess p−q travels distance 3 instead of 1, adding 2(p−q) to the baseline cost 1. This result is specific to one-dimensional absolute-distance cost.

A detail that matters

Choosing the globally nearest pair first is not a valid general transport algorithm.

Keep the connection going

One idea leads to another.

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