Difference between revisions of "Cumulate"
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! [[Cumulate]](X,I) → | ! [[Cumulate]](X,I) → | ||
| 8 || 10 || 10 || 15 || 12 || 19 | | 8 || 10 || 10 || 15 || 12 || 19 | ||
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|} | |} | ||
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Array Functions | Array Functions | ||
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| + | = Optional Parameters = | ||
| + | |||
| + | == Cumulate(A,I,passNull:true) == | ||
| + | |||
| + | When the optional «passNull» is omitted or false, [[Cumulate]] ignores [[Null]] values. In that case they have essentially the same effect as a zero, unless they happen to be the first value in «A», in which case they are passed since no numeric values are yet obtained. | ||
| + | |||
| + | When «passNull» is explicitly set to true, then [[Null]] values are passed through as [[Null]] in the result. | ||
| + | |||
| + | :{| border="1" | ||
| + | ! B → | ||
| + | | [[«null»]] || [[«null»]] || 4 || 1 || [[«null»]] || [[«null»]] || 1 || 9 || 3 || 2 || [[«null»]] | ||
| + | |- | ||
| + | ! [[Cumulate]](B,I) → | ||
| + | | [[«null»]] || [[«null»]] || 4 || 5 || 5 || 5 || 6 || 15||18 || 20|| 20 | ||
| + | |- | ||
| + | ! [[Cumulate]](B,I,passNull:false) → | ||
| + | | [[«null»]] || [[«null»]] || 4 || 5 || 5 || 5 || 6 || 15||18 || 20|| 20 | ||
| + | |- | ||
| + | ! [[Cumulate]](B,I,passNull:true) → | ||
| + | | [[«null»]] || [[«null»]] || 4 || 5 || [[«null»]] || [[«null»]] || 6 || 15||18 || 20|| [[«null»]] | ||
| + | |} | ||
| + | |||
= Notes = | = Notes = | ||
Revision as of 22:11, 11 June 2010
Cumulate(X,I)
Returns an array with each element being the sum of all of the elements of X along dimension I up to, and including, the corresponding element of X.
Declaration
Cumulate(X:Array[I] ; I : Index)
Library
Array Functions
Examples
| I → | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|
| X → | 8 | 2 | 0 | 5 | -3 | 7 |
| Cumulate(X,I) → | 8 | 10 | 10 | 15 | 12 | 19 |
Library
Array Functions
Optional Parameters
Cumulate(A,I,passNull:true)
When the optional «passNull» is omitted or false, Cumulate ignores Null values. In that case they have essentially the same effect as a zero, unless they happen to be the first value in «A», in which case they are passed since no numeric values are yet obtained.
When «passNull» is explicitly set to true, then Null values are passed through as Null in the result.
B → «null» «null» 4 1 «null» «null» 1 9 3 2 «null» Cumulate(B,I) → «null» «null» 4 5 5 5 6 15 18 20 20 Cumulate(B,I,passNull:false) → «null» «null» 4 5 5 5 6 15 18 20 20 Cumulate(B,I,passNull:true) → «null» «null» 4 5 «null» «null» 6 15 18 20 «null»
Notes
Recumulate
A useful variation is the Recumulate function, which resets the total to zero at selected points. This usage is:
Recumulate(x,b,I)
where b is an array of booleans indexed by I, having 1 at each point where the cumulation is to be reset to zero. Recumulate is implemented as a User-Defined Function in the example Recumulate example.ana. A clever usage of this function computes the number of time steps that the system has been in the same state (see the example).
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