30 lines
1.1 KiB
Markdown
30 lines
1.1 KiB
Markdown
# Lattice Measurement
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Detect and measure periodic lattice structures from ACF or FFT peak positions. Reports lattice vectors and angles. Equivalent to Gwyddion's measure_lattice.c module.
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## Inputs
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| Name | Type | Required | Description |
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|------|------|----------|-------------|
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| field | DATA_FIELD | Yes | Input field with periodic structure |
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## Outputs
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| Name | Type | Description |
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|------|------|-------------|
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| correlation | DATA_FIELD | ACF or FFT magnitude used for detection |
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| measurements | RECORD_TABLE | Detected lattice vectors, spacings, and angle |
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## Controls
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| Name | Type | Default | Description |
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|------|------|---------|-------------|
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| method | dropdown | acf | Detection method: acf (autocorrelation) or fft (Fourier transform) |
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## Notes
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- ACF method finds the strongest off-center peaks in the 2D autocorrelation. Works well for real-space periodic structures.
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- FFT method finds peaks in the power spectrum. Better for weak periodicity or noisy data.
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- Reports up to two lattice vectors (a, b), their magnitudes, and the angle between them.
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- For best results, the field should contain at least 3–4 complete periods in each direction.
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