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THIS IS DOCUMENTATION FOR AN OBSOLETE PRODUCT.
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Discrete Calculus
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DiscreteShift
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Discrete Mathematics
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Discrete Calculus
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DiscreteShift
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BUILT-IN MATHEMATICA SYMBOL
DifferenceDelta
DiscreteRatio
RSolve
GeneratingFunction
ReplaceAll
See Also »
|
Discrete Calculus
Summary of New Features in 7.0
New in 7.0: Alphabetical Listing
New in 7.0: Mathematics & Algorithms
More About »
DiscreteShift
DiscreteShift
gives the discrete shift
.
DiscreteShift
gives the multiple shift
.
DiscreteShift
gives the multiple shift of step
h
.
DiscreteShift
computes partial shifts with respect to
i
,
j
, ....
MORE INFORMATION
DiscreteShift
can be input as
. The character
is entered using
Esc
shift
Esc
or
\[DiscreteShift]
. The variable
i
is entered as a subscript.
All quantities that do not explicitly depend on the variables given are taken to have constant partial shift.
DiscreteShift
can be input as
. The character
\[InvisibleComma]
, entered as
Esc
,
Esc
, can be used instead of the ordinary comma.
DiscreteShift
can be input as
.
DiscreteShift
[
f
,
...
,
Assumptions
->
assum
]
uses the assumptions
assum
in the course of computing discrete shifts.
EXAMPLES
CLOSE ALL
Basic Examples
(4)
Shift with respect to
i
:
Shift with step
h
:
Multiple shifts with respect to
i
:
Enter
using
Esc
shift
Esc
, and subscripts using
Ctrl
+
_
:
The shift with respect to
i
of scoped operators:
Shift with respect to
i
:
In[1]:=
Out[1]=
Shift with step
h
:
In[2]:=
Out[2]=
Multiple shifts with respect to
i
:
In[1]:=
Out[1]=
In[2]:=
Out[2]=
Enter
using
Esc
shift
Esc
, and subscripts using
Ctrl
+
_
:
In[1]:=
Out[1]=
The shift with respect to
i
of scoped operators:
In[1]:=
Out[1]=
In[2]:=
Out[2]=
In[3]:=
Out[3]=
Scope
(10)
Compute the first and second shift:
First and second shift with step
h
:
The first partial shifts with respect to
i
and
j
:
Higher partial shifts:
Partial shifts with steps
r
and
s
:
Elementary functions:
Integer functions:
Holonomic sequences satisfy a linear difference equation:
Sums:
Shifting inside the summation sign:
In this case
i
is not a free variable:
Products:
Differencing product limits:
Integrals:
Shifting integration limits:
Limits:
Here the
i
is not a free variable:
Applications
(2)
Define a symbolic mean operator using
DiscreteShift
:
It also works with scoping constructs:
Use on special functions:
Use
DiscreteShift
to define derivatives:
Properties & Relations
(3)
DiscreteShift
is a linear operator:
Product rule:
Quotient rule:
Chain rule:
DiscreteShift
can be expressed in terms of
DifferenceDelta
:
DifferenceDelta
can be expressed in terms of
DiscreteShift
:
DiscreteRatio
can be expressed in terms of
DiscreteShift
:
Possible Issues
(1)
Using
ReplaceAll
to implement
DiscreteShift
can be dangerous:
DiscreteShift
understands scoping rules:
SEE ALSO
DifferenceDelta
DiscreteRatio
RSolve
GeneratingFunction
ReplaceAll
MORE ABOUT
Discrete Calculus
Summary of New Features in 7.0
New in 7.0: Alphabetical Listing
New in 7.0: Mathematics & Algorithms
New in 7