Animation 12

Translation of functions preserves their shape

symmetry-function-translation-shape.mp4

These are sparse samples decoded from the current MP4, not newly rendered illustrations. They can support checks of the sampled states and labels, but cannot establish continuous motion, timing, transitions, or the absence of problems between samples. Use the full MP4 when judging those properties.

1280 × 620 · 24 fps · 5.5 s · 132 frames · 12 samples

MP4 SHA-256 70b781ea9a0259674c356828596b2f59ecf49ed5e6daee2fff5b9d0fe5bfe166

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Chapter context

Section: Translations and Function Representation. Excerpts are verbatim; line numbers refer to the included chapter markdown.

Caption

Translation of functions preserves their shape

Image description

Translation preserving a function shape

Before the animation

Chapter lines 561–561

This makes sense. Translational symmetry needs an object to translate, just as $D_3$ symmetry needs a triangly thing to translate. We can think of the function as a shape. If a system possesses translational symmetry, that shape is preserved.

Chapter lines 563–563

This describes how the function transforms. Whether the physical system it describes behaves the same way after translation is a separate question.

After the animation

Chapter lines 571–571

Indeed, this representation is completely analogous to our 3 dimensional representation of $D_3$. There a vertex contained a component value, here an input value does. Indeed, the $D_3$ representation is itself a function representation, with a domain that contains only three members and is cyclic.

Generation source

Run the main script without --poster-only to draw and encode the translated-function frames. FFmpeg is resolved from configuration, the local tool installation, PATH, or imageio-ffmpeg. No local Python imports or input movie are used.

Mapping evidence and limits

main() explicitly writes symmetry-function-translation-shape.mp4; constants specify 1280 x 620, 24 fps, 132 frames. No matching validation JSON is present. Attribution is by source/output name and pipeline, not a recorded movie hash.

Source SHA-256 values identify the exact downloadable bytes in this packet. The source mapping and recorded checks explain the likely generation pipeline; they do not prove that these exact source bytes produced the movie. A GitHub link pinned to a commit is provided only when the delivered source bytes exactly match that path at the build's Git HEAD.

Decoded contact sheet

Extraction method: Twelve evenly spaced decoded frame indices, including first and last. Native-resolution JPEGs from the encoded MP4; timestamps read from FFmpeg showinfo. No source rerendering. Frame indices are zero-based. Sparse samples do not establish continuous motion or capture every transition.. Frame indices are zero-based.

Timestamped decoded frames from symmetry-function-translation-shape.mp4
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Full-size sampled frames

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