|
evalindets - transform all subexpressions of a given type
|
|
Calling Sequence
|
|
evalindets( expr, atype, transformer, rest )
evalindets[flat]( expr, atype, transformer, rest )
|
|
|
Parameters
|
|
|
expr
|
-
|
anything; any Maple expression
|
|
atype
|
-
|
type; any Maple type expression
|
|
transformer
|
-
|
anything; an expression (typically, a procedure) to be called on each subexpression processed
|
|
rest
|
-
|
anything; (optional) expression sequence of extra arguments to be passed to transformer
|
|
|
|
|
|
Description
|
|
|
•
|
The command evalindets is a particular combination of calls to eval and indets that allows you to efficiently transform all subexpressions of a given type by some algorithm. It encapsulates a common "pattern" used in expression manipulation and transformation.
|
|
•
|
Each subexpression of type atype is transformed by the supplied transformer procedure to produce a "replacement" for it. Then, each subexpression is replaced in the original expression using eval with the corresponding transformed expression.
|
|
•
|
The flat option indicates that the subexpressions of expr of type atype are not nested. This provides a hint to Maple that it can use a somewhat faster algorithm in this special case. If the flat option is passed and nesting occurs, unexpected results may be be produced.
|
|
|
|
Examples
|
|
This example changes every call to  to a call to  .
|
>
|
|
|
| (1) |
|
>
|
+G(4, 1.1), 'float', trunc)](/support/helpjp/helpview.aspx?si=4559/file00809/math126.png)
|
|
| (2) |
|
>
|
, F(x, y)), 'specfunc(anything, F)', proc (f) options operator, arrow; subsop(0 = H, f) end proc)](/support/helpjp/helpview.aspx?si=4559/file00809/math133.png)
|
|
| (3) |
|
>
|
|
|
| (4) |
Shift all symbols by a constant of  .
|
>
|
![evalindets([sin(x), cos(y), tan(z)], 'symbol', proc (y) options operator, arrow; y+Pi end proc)](/support/helpjp/helpview.aspx?si=4559/file00809/math151.png)
|
|
![[-sin(x), -cos(y), tan(z)]](/support/helpjp/helpview.aspx?si=4559/file00809/math154.png)
| (5) |
Expand all products in an expression.
|
>
|
|
|
| (6) |
|
>
|
|
|
| (7) |
|
>
|
|
|
| (8) |
Using evalindets, you can avoid expanding things you might not want expanded.
|
>
|
|
|
| (9) |
Optional arguments may be passed to the transformer.
|
>
|
|
|
| (10) |
|
>
|
|
|
| (11) |
|
>
|
|
|
| (12) |
|
|
Download Help Document
Was this information helpful?
