 |
BUILT-IN MATHEMATICA SYMBOL
ReplacePart
ReplacePart[expr, i->new]
yields an expression in which the 
part of expr is replaced by new.
ReplacePart[expr, {i1->new1, i2->new2, ...}]
replaces parts at positions 
by 
.
ReplacePart[expr, {i, j, ...}->new]
replaces the part at position 
.
ReplacePart[expr, {{i1, j1, ...}->new1, ...}]
replaces parts at positions 
by 
.
ReplacePart[expr, {{i1, j1, ...}, ...}->new]
replaces all parts at positions 
by new.
Details and Options
- Explicit negative part numbers count from the end. »
- Part position specifications can be patterns.
- Each pattern is effectively tested against each list of part numbers for parts in expr.
- Patterns p (such as
) that are not explicitly lists are treated as {p}. - Patterns can include constructs such as
, representing position specifications of variable lengths. - ReplacePart[expr, i:>new] can be used to replace a part without first evaluating it. With a rule such as
, new is evaluated separately for each position that matches patt. - With the default option setting Heads->Automatic, a head is replaced only when the corresponding position specification is explicitly
. - With Heads->True a head is replaced whenever the corresponding position specification matches
. - Heads->False never replaces heads.
- ReplacePart can be used on SparseArray objects.
New in 2 | Last modified in 6
