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--- calculate_functors [2026/07/15 01:13]
hermann
+++ calculate_functors [2026/07/23 03:55] (current)
hermann
@@ Line 375: / Line 375: @@
 > **Availability:** [[Calculate Map]] and [[Calculate Categorical Map]] only.
-These operators compute a neighbourhood statistic and then use the result as an **index** to retrieve a value from either a lookup table or a second image.
+These operators compute a neighbourhood statistic and then use the result as an **index** to retrieve a value from either a connected Lookup Table or a second image. ''TABLE'' below always refers to a **Lookup Table** specifically — see section 5 for the operators that query one directly.
+> If ''TABLE'' is bound to a multi-column Table (not a Lookup Table), an error is reported. See section 6 for multi-column tables.
 **Full syntax:** \\
@@ Line 385: / Line 387: @@
 ''nbN(IMAGE, h, w, IMAGE2)''
-When a **TABLE** is provided: the statistic is used as a key to query the lookup table. \\
+When a **TABLE** (Lookup Table) is provided: the statistic is used as a key to query it, equivalent to ''TABLE[statistic]'' from section 5. \\
 When an **IMAGE2** is provided: the statistic is used as a pixel coordinate to sample ''IMAGE2''.
 ^ Operator ^ Syntax ^ Description ^ Example ^
-| MinRef | ''nbMinRef(...)'' | Finds the minimum in the window, then uses it as an index. | ''nbMinRef(i4, 2, 3, t1, line, column)'' |
+| MinRef | ''nbMinRef(...)'' | Finds the minimum in the window, then uses it as an index into the Lookup Table (or a coordinate into IMAGE2). | ''nbMinRef(i4, 2, 3, t1, line, column)'' |
-| MaxRef | ''nbMaxRef(...)'' | Finds the maximum in the window, then uses it as an index. | ''nbMaxRef(i4, 2, 3, i1, line, column)'' |
+| MaxRef | ''nbMaxRef(...)'' | Finds the maximum in the window, then uses it as an index into the Lookup Table (or a coordinate into IMAGE2). | ''nbMaxRef(i4, 2, 3, i1, line, column)'' |
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@@ Line 401: / Line 403: @@
 **Syntax:** ''nbConvol(IMAGE, TABLE, h, w)'' / ''nbConvol(IMAGE, TABLE, h, w, y, x)''
+> If ''TABLE'' is bound to a multi-column Table (not a Lookup Table), an error is reported. See section 6 for multi-column tables.
 ^ Parameter ^ Meaning ^
 | ''IMAGE'' | The image to convolve (''iX'') |
-| ''TABLE'' | A Table whose entries are the kernel coefficients, indexed 1 to h*w, mapped **left-to-right, top-to-bottom** |
+| ''TABLE'' | A **Lookup Table** whose entries are the kernel coefficients, indexed 1 to h*w, mapped **left-to-right, top-to-bottom**. |
 | ''h'' | Number of kernel rows |
 | ''w'' | Number of kernel columns |
 | ''y'', ''x'' | Anchor position (optional; defaults to window centre) |
-Each cell in the window is assigned a unique integer key, starting at 1 and advancing left-to-right, then top-to-bottom. The ''TABLE'' argument must contain one row per window cell, where the key is that cell's index and the value is its convolution coefficient. The result of ''nbConvol'' is the weighted sum of all pixel values in the window, each multiplied by the coefficient stored at the corresponding key in the table.
+Each cell in the window is assigned a unique integer key, starting at 1 and advancing left-to-right, then top-to-bottom. The ''TABLE'' argument must be a Lookup Table containing one row per window cell, where the key is that cell's index and the value is its convolution coefficient. The result of ''nbConvol'' is the weighted sum of all pixel values in the window, each multiplied by the coefficient stored at the corresponding key in the table.
 The grids below illustrate the index mapping for some common window sizes:
@@ Line 891: / Line 895: @@
 | Calculate Lookup Table Values | ''CalculateLookupTableValues'' |
 | Calculate Lookup Table Keys and Values | ''CalculateLookupTableKeysAndValues'' |