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convert/list

 

Calling Sequence

Parameters

Description

Examples

Compatibility

Calling Sequence

convert( expr, list, expected_type )

convert( expr, list, nested_op )

Parameters

expr

-

expression to convert

expected_type

-

(optional) `+`, `*`, or `^`

nested_op

-

(optional) option of the form nested=true or false; whether to preserve structure of rtables and arrays

Description

• 

This command can be used to convert a variety of expressions into list form.  The precise form of the result is determined by the input and the nested_op and expected_type options.

• 

The use of the expected_type option enables the convenient extraction of terms, factors or (base, exponent) pairs without worrying about the trivial cases. If expected_type is given and expr is not of type expected_type, expr is interpreted trivially to be of that type: a sum of one term, a product of one factor, or a power with exponent 1. The return value is [expr, 1] if expected_type=`^`, and [expr] otherwise.

• 

The nested_op option is only relevant if the input expr is an rtable (Matrix, Array, or Vector) or array, matrix, or vector.

Input type

nested option

Output form

rtable

nested=false

single-level (flattened) list

rtable

nested or nested=true

nested list with structure reflecting input (*)

array, matrix, vector

nested=false

single-level (flattened list)

array, matrix, vector

nested or nested=true

nested list with structure reflecting input

table with integer indices

 

list ordered by table index

other table

 

unordered list

string

 

list of characters (equivalent to StringTools[Explode])

MultiSet

 

[ op(Entries(expr)) ]

other

 

[ op(expr) ]

(*) If the rtable is 0-dimensional, the empty list is returned, rather than NULL.

• 

Note that when converting an rtable to unnested list form, the order of elements in the output list will depend on the storage order of the rtable.

Examples

convertabc,list

a,b,c

(1)

AArray3..4,1..1,0..3,i,j,k→j+ki:

convertA,list

13,14,0,0,13,14,0,0,13,14,23,12,13,14,23,12,1,34,23,12,1,34,43,1

(2)

convertA,list,nested

13,0,13,23,0,13,23,1,13,23,1,43,14,0,14,12,0,14,12,34,14,12,34,1

(3)

convertArray,list

(4)

convert1|2,3|4,list

1,3,2,4

(5)

convertMatrix1|2,3|4,order=C_order,list

1,2,3,4

(6)

convertfa,b,c,list

a,b,c

(7)

The default behavior is to extract operands:

`~`convertx2,x2+2x,x2+2x+1,list

x,2,x2,2x,x2,2x,1

(8)

By setting `+` as the expected_type, one can extract terms instead:

`~`convertx2,x2+2x,x2+2x+1,list,`+`

x2,x2,2x,x2,2x,1

(9)

Now get the factors in each term:

`~`convertx2,2x,1,list,`*`

x2,2,x,1

(10)

And the bases and exponents:

`~`convertx2,x,1,list,`^`

x,2,x,1,1,1

(11)

Compatibility

• 

The expected_type parameter was introduced in Maple 18.

• 

For more information on Maple 18 changes, see Updates in Maple 18.

See Also

convert

convert/set

entries

StringTools[Explode]