Single Float Range Loop

Some sweeps are integers and some aren't, and the "aren't" ones are often where the real gains hide. CFG at 3.5 vs 4.0, denoise at 0.5 vs 0.6, a timestep shift at 5.5 vs 6.5 - you can't step those with the int loop. SingleFloatLoop is the float version: it walks a value through a range with a decimal step, one value per queue run, and hands it to whatever input you wire it into.

It's the quiet workhorse of KY-2000's RES4LYF-tester-loop pack. The pack is best known for sweeping RES4LYF samplers and schedulers, but this node doesn't care about RES4LYF at all - it's a plain, reliable range loop that shines whenever you're fine-tuning a continuous parameter across a handful of runs instead of guessing at a single value.

How it works

Each execution advances a counter and emits the next value from an inclusive range: start through end stepping by step, rounded to six decimal places to dodge float drift - that's the 0.1 accumulation bug that makes naive loops come out with 0.30000000000000004; this one won't. Descending ranges work (start: 2.0, end: 0.5 steps down), and negative step handling is normalized for you. mode selects sequential, random (seeded via seed), or ping_pong; reset (true) restarts the counter.

Outputs: value (the FLOAT you connect onward), plus current_index, total_combinations, and a current_combination string for captions or filenames.

The inputs that matter

• start / end / step - the range; step minimum is 0.000001.
• mode - sequential / random / ping_pong.
• seed - reproducible random mode.
• reset - start over.

Install

From the pack repo, in ComfyUI/custom_nodes/:

cd ComfyUI/custom_nodes/
git clone https://github.com/KY-2000/RES4LYF-tester-loop.git

Restart ComfyUI. No dependencies, no model downloads; the node works whether or not you have RES4LYF installed.

Where people get burned

Same shared-state gotcha as its sibling: all instances of the class use one counter, so two SingleFloatLoop nodes in one workflow advance together. Keep one sweep at a time. Also worth remembering before you queue a big sweep - the node's total_combinations output tells you exactly how many runs you're about to commit to. With float ranges it's easy to build a step that implies hundreds of runs without noticing; read the counter first.