29 lines
1.0 KiB
Markdown
29 lines
1.0 KiB
Markdown
# Cross-Correlate
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Compute 2D cross-correlation between two fields. The correlation peak indicates the offset where the two fields best match. Useful for drift measurement and feature alignment. Equivalent to Gwyddion crosscor.c.
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## Inputs
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| Name | Type | Required | Description |
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|------|------|----------|-------------|
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| field_a | DATA_FIELD | Yes | First input field |
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| field_b | DATA_FIELD | Yes | Second input field |
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## Outputs
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| Name | Type | Description |
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|------|------|-------------|
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| correlation | DATA_FIELD | Cross-correlation map |
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## Controls
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| Name | Type | Default | Description |
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|------|------|---------|-------------|
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| mode | dropdown | same | Output size: full (Na+Nb−1), same (same as field_a), or valid (overlapping region only) |
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| normalize | BOOLEAN | True | Normalize the result to [−1, 1] by dividing by the product of RMS values |
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## Notes
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- Both fields must be of compatible numpy array types; very different sizes in full mode produce large outputs.
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- Mean is subtracted before correlation; absolute offset information is lost.
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