BilateralZTransform
✖
BilateralZTransform
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
. In some cases, the annulus of definition may extend to the exterior or the interior of a disk.
- The following options can be given:
-
AccuracyGoal Automatic digits of absolute accuracy sought Assumptions $Assumptions assumptions to make about parameters GenerateConditions True whether to generate answers that involve conditions on parameters Method Automatic method to use PerformanceGoal $PerformanceGoal aspects of performance to optimize PrecisionGoal Automatic digits of precision sought WorkingPrecision Automatic the precision used in internal computations

Examples
open allclose allBasic Examples (2)Summary of the most common use cases
Define an exponentially decaying sequence:

https://wolfram.com/xid/0cf3k8echl8hdhu-nf2iyf

https://wolfram.com/xid/0cf3k8echl8hdhu-zdczeb

Compute its bilateral Z transform:

https://wolfram.com/xid/0cf3k8echl8hdhu-17ori4

Complex plot of the bilateral Z transform:

https://wolfram.com/xid/0cf3k8echl8hdhu-zkutn2

Compute the transform at a single point:

https://wolfram.com/xid/0cf3k8echl8hdhu-os2l29

Compute the bilateral Z transform of a multivariate function:

https://wolfram.com/xid/0cf3k8echl8hdhu-p2fa1w

Scope (8)Survey of the scope of standard use cases
Bilateral Z transform of the UnitStep function:

https://wolfram.com/xid/0cf3k8echl8hdhu-es4cbg


https://wolfram.com/xid/0cf3k8echl8hdhu-eeimj5

Combination of power functions:

https://wolfram.com/xid/0cf3k8echl8hdhu-pj2hd7

https://wolfram.com/xid/0cf3k8echl8hdhu-5k7ndw


https://wolfram.com/xid/0cf3k8echl8hdhu-tl7blc


https://wolfram.com/xid/0cf3k8echl8hdhu-6msr78


https://wolfram.com/xid/0cf3k8echl8hdhu-b0z71z

Discrete-time, finite support function:

https://wolfram.com/xid/0cf3k8echl8hdhu-rr4kbk

https://wolfram.com/xid/0cf3k8echl8hdhu-91vyk


https://wolfram.com/xid/0cf3k8echl8hdhu-d2162z


https://wolfram.com/xid/0cf3k8echl8hdhu-9dyuj6

Calculate the bilateral Z transform at a single point:

https://wolfram.com/xid/0cf3k8echl8hdhu-r95ho8

Alternatively, calculate the transform symbolically:

https://wolfram.com/xid/0cf3k8echl8hdhu-5iz9zs

Then evaluate it for a specific value of :

https://wolfram.com/xid/0cf3k8echl8hdhu-guyg4n

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

https://wolfram.com/xid/0cf3k8echl8hdhu-8ejzz5

https://wolfram.com/xid/0cf3k8echl8hdhu-cnps4y

Plot the bilateral Z transform using numerical values only:

https://wolfram.com/xid/0cf3k8echl8hdhu-vhht9g

Options (3)Common values & functionality for each option
Assumptions (1)
Specify the range for a parameter using Assumptions:

https://wolfram.com/xid/0cf3k8echl8hdhu-7b89pa

GenerateConditions (1)
Set GenerateConditions to False to obtain a result without conditions:

https://wolfram.com/xid/0cf3k8echl8hdhu-lydhtt

WorkingPrecision (1)
Use WorkingPrecision to obtain a result with arbitrary precision:

https://wolfram.com/xid/0cf3k8echl8hdhu-6b89z8


https://wolfram.com/xid/0cf3k8echl8hdhu-rbcm49


https://wolfram.com/xid/0cf3k8echl8hdhu-tvz7hd

Applications (2)Sample problems that can be solved with this function
Define finite duration signals:

https://wolfram.com/xid/0cf3k8echl8hdhu-odw50u
Plot the signals in the time domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-1j0iuw

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

https://wolfram.com/xid/0cf3k8echl8hdhu-gnkwgz

Then, perform inversion back to the time domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-jifxa

Plot the convolution in the time domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-pxerld

Alternatively, find the convolution using DiscreteConvolve:

https://wolfram.com/xid/0cf3k8echl8hdhu-xtbjle

Define infinite duration signals:

https://wolfram.com/xid/0cf3k8echl8hdhu-oi8vv9
Plot the signals in the time domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-c9q86j

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

https://wolfram.com/xid/0cf3k8echl8hdhu-ynr2m

Perform the inversion back to the time domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-s9r5cz

Plot the convolution in the time domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-509yxw

Alternatively, find the convolution using DiscreteConvolve:

https://wolfram.com/xid/0cf3k8echl8hdhu-zarpcw

Properties & Relations (7)Properties of the function, and connections to other functions
BilateralZTransform and InverseBilateralZTransform are mutual inverses:

https://wolfram.com/xid/0cf3k8echl8hdhu-6suicg


https://wolfram.com/xid/0cf3k8echl8hdhu-3cfti4

BilateralZTransform is closely related to FourierSequenceTransform:

https://wolfram.com/xid/0cf3k8echl8hdhu-19m1r9


https://wolfram.com/xid/0cf3k8echl8hdhu-mlx09s


https://wolfram.com/xid/0cf3k8echl8hdhu-6ftlb


https://wolfram.com/xid/0cf3k8echl8hdhu-bnobea


https://wolfram.com/xid/0cf3k8echl8hdhu-ey7htn


https://wolfram.com/xid/0cf3k8echl8hdhu-3e8tzj

Differentiation in the -domain:

https://wolfram.com/xid/0cf3k8echl8hdhu-oeuhri

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
]}
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
]}