id
-- the identity mapid(
x)
evaluates and returns
x
.
id(x)
id(x1, x2...)
x, x1, x2, ... |
- | arbitrary MuPAD objects |
the sequence of the input parameters.
id(
x)
evaluates and returns
x
; id(
x1, x2, ...)
returns the
evaluated arguments as an expression
sequence; id(
)
returns the void object
null()
.id
is a function of the system kernel.id
returns the evaluated arguments:
>> a := 2: id(a + 2)
4
>> id(a, b, 4 + 2)
2, b, 6
id(
)
returns null()
:
>> domtype(id())
DOM_NULL
>> delete a:
id
is useful when working with functional
expressions:
>> f := 3*id + sin + 5*id^2 + exp@(-id^2): f(x)
2 2 3 x + sin(x) + 5 x + exp(- x )
>> D(f)
2 10 id + cos - 2 id exp@- id + 3
>> delete f: