Difference between revisions of "IndexesOf"

Latest revision as of 00:06, 19 November 2024

IndexesOf(a, except...)

Returns a list of handles to the indexes of array «a». It is different from IndexNames(a), which returns the identifiers of the indexes as text values instead of handles.

If «X» has an implicit index (an index without a name), the first element of the output list is null, rather than a handle.

If the array has more than one local index with the same identifier, you can use IndexesOf(a) to identify each index safely because each handle unambiguously refers to the corresponding index, where IndexNames(a) would return the identifiers as identical and therefore ambiguous text values.

The optional «except» parameter excludes any of the indexes that are listed.

Syntax:

IndexesOf(a: Array)

Example

IndexesOf(Car_prices) → [Car_types, Year]

IndexesOf(Car_prices, except: Car_types) → [Year]

Find the maximum in A over all indexes:

Max( A, ...IndexesOf(A) )

Sum over all indexes of x except J and K:

Sum( x, ...IndexesOf(x, except: J,K) )

History

The «except» parameter was introduced in Analytica 5.2.

@@ Line 3: / Line 3: @@
 [[Category:Meta-Inference Functions]]
+== IndexesOf(a'', except...'') ==
+Returns a list of [[handle]]s to the indexes of array «a». It is different from [[IndexNames]](a), which returns the identifiers of the indexes as text values instead of handles.
-= IndexesOf(a) =
+If «X» has an [[implicit index]] (an index without a name), the first element of the output list is [[null]], rather than a handle.
-Returns a list of handles to the indexes of array a. It is different from IndexNames(A), which returns the identifiers of the index variables as text values, instead of handles.
+If the array has more than one [[Local Indexes|local index]] with the same identifier, you can use [[IndexesOf]](a) to identify each index safely because each handle unambiguously refers to the corresponding index, where [[IndexNames]](a) would return the identifiers as identical and therefore ambiguous text values.
-Sometimes an array has more than one local index with the same identifier. In this case, you can use IndexesOf(a) to identify each index safely because each handle unambiguously refers to the coresponding index, where IndexNames(a) would return the identifiers as identical and therefore ambiguous text values.
+The optional «except» parameter excludes any of the indexes that are listed.
+[[Syntax]]:
+:[[IndexesOf]](a: Array)
-=== Example ===
+== Example ==
+:<code>IndexesOf(Car_prices) &rarr; [Car_types, Year]</code>
- IndexNames(Car_prices) --> [Car_types, Year]
+:<code>IndexesOf(Car_prices, except: Car_types) &rarr; [Year]</code>
-Syntax: IndexesOf(a: Array)
+Find the maximum in <code>A</code> over all indexes:
+:<code>[[Max]]( A, ...[[IndexesOf]](A) )</code>
+Sum over all indexes of <code>x</code> except <code>J</code> and <code>K</code>:
+:<code>[[Sum]]( x, ...[[IndexesOf]](x, except: J,K) )</code>
-Retrieved from "http://lumina.com/wiki/index.php/VarTerm_Functions"
+== History ==
+* The «except» parameter was introduced in [[Analytica 5.2]].
 == See Also ==
+* [[Handle]]
 * [[Handle Functions]]
 * [[IndexNames]]
+* [[Repeated parameter forwarding]]