Math Constants | Basic

MathConstants ("Math Constants | Basic") is a dropdown that hands you a famous number, and honestly, it's the node you'll use once and then keep around for the two options that aren't famous at all. Pick a constant from five choices - pi, e, tau, inf, nan - and get a FLOAT out.

The mechanism is unglamorous: it's Python's math module values, passed through. pi is 3.14159..., e is Euler's number, tau is 2π (the one some people argue should be the real circle constant). But the interesting pair is inf (infinity) and nan (not-a-number) - those are the two that show up when your math goes sideways, and this node is a legitimate way to inject them deliberately.

The inputs that matter

• constant - the one and only input. Dropdown: pi, e, tau, inf, nan.

The output FLOAT wires into anything that takes a number.

Why you'd reach for it

Honest takes, in order of usefulness:

• nan is the debugging superpower. Feed it into a math node and every value downstream becomes nan - instantly tracing which path a bad value travels through your graph. It's the graph version of a probe.
• inf for sentinel values. Sometimes you want a number larger than anything real so a min operation ignores it, or smaller than anything so a max ignores it. Infinity is perfect for that.
• pi / tau for anything circular - rotation math, seamless-tile work, animated angle sweeps. You'll typically fold it into a BasicMath node with a multiplication.
• e - the one you'll probably never use, but it's there if you're doing exponential scheduling.

Installing it

Same install as every node in this pack - pure Python, no dependencies, no models:

cd ComfyUI/custom_nodes
git clone https://github.com/akatz-ai/ComfyUI-Basic-Math

Restart ComfyUI, find it under Basic Math ➕ → Constants. Or use ComfyUI Manager → Install Custom Nodes → search "ComfyUI-Basic-Math".

The gotchas

The big one: nan doesn't compare equal to anything, including itself. If you're checking "is this result nan?" with a NumberComparison and ==, it will never match - that's IEEE 754 behavior, not a bug in the node. And inf and nan are floats, so they'll flow through as FLOAT. Also, remember the menu shows "Math Constants | Basic" - the | Basic suffix is the pack's naming convention. If you find yourself reaching for pi in multiple workflows, this node saves you typing 3.14159 into a widget and hoping you remembered enough digits.