WOLFRAM

gives the bilateral Z transform of expr.

BilateralZTransform[expr,{n1,,nk},{z1,,zk}]

gives the multidimensional bilateral Z transform of expr.

Details and Options

  • The bilateral Z transform is the discrete analog of the bilateral Laplace transform and plays an important role in digital signal processing and other fields.
  • The bilateral Z transform for a discrete function is given by .
  • The multidimensional bilateral Z transform is given by .
  • The sum is computed using numerical methods if the third argument, z, is given a numerical value.
  • The bilateral Z transform of exists only for complex values of in an annulus given by alpha<TemplateBox[{z}, Abs]<beta. In some cases, the annulus of definition may extend to the exterior or the interior of a disk.
  • The following options can be given:
  • AccuracyGoalAutomaticdigits of absolute accuracy sought
    Assumptions $Assumptionsassumptions to make about parameters
    GenerateConditions Truewhether to generate answers that involve conditions on parameters
    MethodAutomaticmethod to use
    PerformanceGoal$PerformanceGoalaspects of performance to optimize
    PrecisionGoalAutomaticdigits of precision sought
    WorkingPrecision Automaticthe precision used in internal computations

Examples

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Basic Examples  (2)Summary of the most common use cases

Define an exponentially decaying sequence:

Out[2]=2

Compute its bilateral Z transform:

Out[3]=3

Complex plot of the bilateral Z transform:

Out[6]=6

Compute the transform at a single point:

Out[4]=4

Compute the bilateral Z transform of a multivariate function:

Out[1]=1

Scope  (8)Survey of the scope of standard use cases

Bilateral Z transform of the UnitStep function:

Out[2]=2

Discrete power function:

Out[1]=1

Combination of power functions:

Out[2]=2
Out[3]=3
Out[4]=4

DiscreteDelta:

Out[1]=1

Discrete-time, finite support function:

Out[2]=2

Trigonometric sequence:

Out[1]=1
Out[2]=2

Calculate the bilateral Z transform at a single point:

Out[1]=1

Alternatively, calculate the transform symbolically:

Out[2]=2

Then evaluate it for a specific value of :

Out[3]=3

For some functions, the bilateral Z transform can be evaluated only numerically:

Out[2]=2

Plot the bilateral Z transform using numerical values only:

Out[3]=3

Options  (3)Common values & functionality for each option

Assumptions  (1)

Specify the range for a parameter using Assumptions:

Out[1]=1

GenerateConditions  (1)

Set GenerateConditions to False to obtain a result without conditions:

Out[1]=1

WorkingPrecision  (1)

Use WorkingPrecision to obtain a result with arbitrary precision:

Out[1]=1
Out[2]=2
Out[3]=3

Applications  (2)Sample problems that can be solved with this function

Define finite duration signals:

Plot the signals in the time domain:

Out[3]=3

To find the convolution, first calculate the product of the transforms:

Out[4]=4

Then, perform inversion back to the time domain:

Out[5]=5

Plot the convolution in the time domain:

Out[6]=6

Alternatively, find the convolution using DiscreteConvolve:

Out[7]=7

Define infinite duration signals:

Plot the signals in the time domain:

Out[2]=2

To find the convolution, first calculate product of the transforms:

Out[3]=3

Perform the inversion back to the time domain:

Out[4]=4

Plot the convolution in the time domain:

Out[5]=5

Alternatively, find the convolution using DiscreteConvolve:

Out[6]=6

Properties & Relations  (7)Properties of the function, and connections to other functions

BilateralZTransform and InverseBilateralZTransform are mutual inverses:

Out[2]=2
Out[3]=3

BilateralZTransform is closely related to FourierSequenceTransform:

Out[1]=1
Out[2]=2

Linearity:

Out[1]=1

Time shifting:

Out[1]=1

Scaling in the -domain:

Out[1]=1

Convolution:

Out[1]=1

Differentiation in the -domain:

Out[1]=1

Neat Examples  (1)Surprising or curious use cases

Create a table of basic bilateral Z transforms:

Wolfram Research (2021), BilateralZTransform, Wolfram Language function, https://reference.wolfram.com/language/ref/BilateralZTransform.html.
Wolfram Research (2021), BilateralZTransform, Wolfram Language function, https://reference.wolfram.com/language/ref/BilateralZTransform.html.

Text

Wolfram Research (2021), BilateralZTransform, Wolfram Language function, https://reference.wolfram.com/language/ref/BilateralZTransform.html.

Wolfram Research (2021), BilateralZTransform, Wolfram Language function, https://reference.wolfram.com/language/ref/BilateralZTransform.html.

CMS

Wolfram Language. 2021. "BilateralZTransform." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/BilateralZTransform.html.

Wolfram Language. 2021. "BilateralZTransform." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/BilateralZTransform.html.

APA

Wolfram Language. (2021). BilateralZTransform. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/BilateralZTransform.html

Wolfram Language. (2021). BilateralZTransform. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/BilateralZTransform.html

BibTeX

@misc{reference.wolfram_2025_bilateralztransform, author="Wolfram Research", title="{BilateralZTransform}", year="2021", howpublished="\url{https://reference.wolfram.com/language/ref/BilateralZTransform.html}", note=[Accessed: 26-March-2025 ]}

@misc{reference.wolfram_2025_bilateralztransform, author="Wolfram Research", title="{BilateralZTransform}", year="2021", howpublished="\url{https://reference.wolfram.com/language/ref/BilateralZTransform.html}", note=[Accessed: 26-March-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_bilateralztransform, organization={Wolfram Research}, title={BilateralZTransform}, year={2021}, url={https://reference.wolfram.com/language/ref/BilateralZTransform.html}, note=[Accessed: 26-March-2025 ]}

@online{reference.wolfram_2025_bilateralztransform, organization={Wolfram Research}, title={BilateralZTransform}, year={2021}, url={https://reference.wolfram.com/language/ref/BilateralZTransform.html}, note=[Accessed: 26-March-2025 ]}