MAProcess
✖
MAProcess
Details

- MAProcess is also known as a finite impulse response (FIR) filter.
- MAProcess is a discrete-time and continuous-state random process.
- The MA process is described by the difference equation
, where
is the state output,
is white noise input,
is the shift operator, and the constant c is taken to be zero if not specified.
- The initial data init can be given as a list {…,y[-2],y[-1]} or a single-path TemporalData object with time stamps understood as {…,-2,-1}.
- A scalar MA process should have real coefficients bi and c, and a positive variance v.
- An
-dimensional vector MA process should have real coefficient matrices bi of dimensions
×
, real vector c of length
, and the covariance matrix Σ should be symmetric positive definite of dimensions
×
.
- The MA process with zero constant has transfer function
where:
-
scalar process vector process; is the
×
identity matrix
- MAProcess[tproc,q] for a time series process tproc gives an MA process of order q such that the series expansions about zero of the corresponding transfer functions agree up to degree q.
- Possible time series processes tproc include ARProcess, ARMAProcess, and SARIMAProcess.
- MAProcess[q] represents a moving-average process of order q for use in EstimatedProcess and related functions.
- MAProcess can be used with such functions as CovarianceFunction, RandomFunction, and TimeSeriesForecast.
Examples
open allclose allBasic Examples (3)Summary of the most common use cases

https://wolfram.com/xid/0bdo2w6eq-64nrvs


https://wolfram.com/xid/0bdo2w6eq-8f61zv


https://wolfram.com/xid/0bdo2w6eq-2zyt26


https://wolfram.com/xid/0bdo2w6eq-8ntq29


https://wolfram.com/xid/0bdo2w6eq-optblb


https://wolfram.com/xid/0bdo2w6eq-0hlz9m

Scope (37)Survey of the scope of standard use cases
Basic Uses (11)
Simulate an ensemble of paths:

https://wolfram.com/xid/0bdo2w6eq-bi9bqw


https://wolfram.com/xid/0bdo2w6eq-iv2byr

Simulate with given precision:

https://wolfram.com/xid/0bdo2w6eq-jsc0w2

Simulate a first-order scalar process:

https://wolfram.com/xid/0bdo2w6eq-pqhada
Sample paths for positive and negative values of the parameter:

https://wolfram.com/xid/0bdo2w6eq-ekggyu

Initial values do not influence the process values:

https://wolfram.com/xid/0bdo2w6eq-9hyjm

https://wolfram.com/xid/0bdo2w6eq-6xxsw7

https://wolfram.com/xid/0bdo2w6eq-l3esgs

https://wolfram.com/xid/0bdo2w6eq-24va9i

Simulate a two-dimensional process:

https://wolfram.com/xid/0bdo2w6eq-2c797h
Create a 2D sample path function from the data:

https://wolfram.com/xid/0bdo2w6eq-jb36gm
The color of the path is the function of time:

https://wolfram.com/xid/0bdo2w6eq-6lfxt1

Create a 3D sample path function with time:

https://wolfram.com/xid/0bdo2w6eq-cekudy
The color of the path is the function of time:

https://wolfram.com/xid/0bdo2w6eq-xys18y

Simulate a three-dimensional process:

https://wolfram.com/xid/0bdo2w6eq-7bosgv
Create a sample path function from the data:

https://wolfram.com/xid/0bdo2w6eq-w11wki
The color of the path is the function of time:

https://wolfram.com/xid/0bdo2w6eq-52vo5x


https://wolfram.com/xid/0bdo2w6eq-bfhter

Compare the sample covariance functions with the one of the estimated process:

https://wolfram.com/xid/0bdo2w6eq-cq0jrs

Use TimeSeriesModel to automatically find orders:

https://wolfram.com/xid/0bdo2w6eq-yx6nir


https://wolfram.com/xid/0bdo2w6eq-8onjon

Compare the sample covariance functions with the best time series model:

https://wolfram.com/xid/0bdo2w6eq-5kfpve

Find maximum likelihood estimator:

https://wolfram.com/xid/0bdo2w6eq-lcxerb

https://wolfram.com/xid/0bdo2w6eq-5o7h03
Fix the constant and the variance and estimate the remaining parameters:

https://wolfram.com/xid/0bdo2w6eq-jwzwml

Plot the log-likelihood function together with the position of the estimated parameters:

https://wolfram.com/xid/0bdo2w6eq-wkev1o

Estimate a vector moving-average process:

https://wolfram.com/xid/0bdo2w6eq-k069f

https://wolfram.com/xid/0bdo2w6eq-j9vn36

Compare covariance functions for each component:

https://wolfram.com/xid/0bdo2w6eq-7or8nu


https://wolfram.com/xid/0bdo2w6eq-0665ch


https://wolfram.com/xid/0bdo2w6eq-h6stbp

Plot the data and the forecasted values:

https://wolfram.com/xid/0bdo2w6eq-xi6f47

Find a forecast for a vector-valued time series process:

https://wolfram.com/xid/0bdo2w6eq-z2srib
Find the forecast for the next 10 steps:

https://wolfram.com/xid/0bdo2w6eq-uxaf8m

Plot the data and the forecast for each component:

https://wolfram.com/xid/0bdo2w6eq-f5ibl8

Covariance and Spectrum (6)
Correlation function exists in closed form:

https://wolfram.com/xid/0bdo2w6eq-r0jluh


https://wolfram.com/xid/0bdo2w6eq-837d4s

Closed form of the partial correlation function for the first order:

https://wolfram.com/xid/0bdo2w6eq-0tn1ym


https://wolfram.com/xid/0bdo2w6eq-47jzgn

Covariance matrix of an MAProcess is symmetric multidiagonal:

https://wolfram.com/xid/0bdo2w6eq-7amqc


https://wolfram.com/xid/0bdo2w6eq-lvthgz

Covariance function for a vector-valued process:

https://wolfram.com/xid/0bdo2w6eq-zgcc07

https://wolfram.com/xid/0bdo2w6eq-q33vkk


https://wolfram.com/xid/0bdo2w6eq-dctitw


https://wolfram.com/xid/0bdo2w6eq-xkw76w

Vector MAProcess:

https://wolfram.com/xid/0bdo2w6eq-v9u1hk

https://wolfram.com/xid/0bdo2w6eq-ytou44

Stationarity and Invertibility (4)
MAProcess is weakly stationary for any choice of parameters:

https://wolfram.com/xid/0bdo2w6eq-3hltd0


https://wolfram.com/xid/0bdo2w6eq-9m9m42

Check if a time series is invertible:

https://wolfram.com/xid/0bdo2w6eq-kcua8e

https://wolfram.com/xid/0bdo2w6eq-6kx0xv


https://wolfram.com/xid/0bdo2w6eq-z54fr4

Find invertible representation for a moving-average process:

https://wolfram.com/xid/0bdo2w6eq-gmdpp


https://wolfram.com/xid/0bdo2w6eq-75inl

The moments are being conserved:

https://wolfram.com/xid/0bdo2w6eq-jlcg78


https://wolfram.com/xid/0bdo2w6eq-1vqmej

Find invertibility conditions:

https://wolfram.com/xid/0bdo2w6eq-b5omx0


https://wolfram.com/xid/0bdo2w6eq-v6ts0h

Find conditions for higher order:

https://wolfram.com/xid/0bdo2w6eq-oza9o4


https://wolfram.com/xid/0bdo2w6eq-rsrsxw

Estimation Methods (6)
The available methods for estimating an MAProcess:

https://wolfram.com/xid/0bdo2w6eq-7sxqvy

https://wolfram.com/xid/0bdo2w6eq-2fm8nv

https://wolfram.com/xid/0bdo2w6eq-6rakjd


https://wolfram.com/xid/0bdo2w6eq-7ea8tb

Method of moments allows following solvers:

https://wolfram.com/xid/0bdo2w6eq-5jqixi

https://wolfram.com/xid/0bdo2w6eq-67oqma

https://wolfram.com/xid/0bdo2w6eq-qcmi0g

This method allows for fixed parameters:

https://wolfram.com/xid/0bdo2w6eq-oza5b7

Some relations between parameters are also permitted:

https://wolfram.com/xid/0bdo2w6eq-d74eyw

Maximum conditional likelihood method allows following solvers:

https://wolfram.com/xid/0bdo2w6eq-n00rv8

https://wolfram.com/xid/0bdo2w6eq-x18r85

https://wolfram.com/xid/0bdo2w6eq-3kgk5y

This method allows for fixed parameters:

https://wolfram.com/xid/0bdo2w6eq-vvocl0

Some relations between parameters are also permitted:

https://wolfram.com/xid/0bdo2w6eq-88rn34

Maximum likelihood method allows following solvers:

https://wolfram.com/xid/0bdo2w6eq-p7a8lf

https://wolfram.com/xid/0bdo2w6eq-78azaw

https://wolfram.com/xid/0bdo2w6eq-2uleaj

This method allows for fixed parameters:

https://wolfram.com/xid/0bdo2w6eq-e4p7s7

Some relations between parameters are also permitted:

https://wolfram.com/xid/0bdo2w6eq-nv6zy5

Spectral estimator allows to specify windows used for PowerSpectralDensity calculation:

https://wolfram.com/xid/0bdo2w6eq-lw5b9u

https://wolfram.com/xid/0bdo2w6eq-xrfcvz

Spectral estimator allows following solvers:

https://wolfram.com/xid/0bdo2w6eq-3g60u2

https://wolfram.com/xid/0bdo2w6eq-2qt7iv

This method allows for fixed parameters:

https://wolfram.com/xid/0bdo2w6eq-s5lz58

Some relations between parameters are also permitted:

https://wolfram.com/xid/0bdo2w6eq-64gzgk


https://wolfram.com/xid/0bdo2w6eq-dks5i2

https://wolfram.com/xid/0bdo2w6eq-bh73p4

This method allows for fixed parameters:

https://wolfram.com/xid/0bdo2w6eq-8jsn0e

Process Slice Properties (5)
Single time SliceDistribution:

https://wolfram.com/xid/0bdo2w6eq-p2tl2v

Multiple time slice distributions:

https://wolfram.com/xid/0bdo2w6eq-cantv6


https://wolfram.com/xid/0bdo2w6eq-418bc

Slice distribution of a vector-valued time series:

https://wolfram.com/xid/0bdo2w6eq-sczdpa

First-order probability density function:

https://wolfram.com/xid/0bdo2w6eq-ej3ae1


https://wolfram.com/xid/0bdo2w6eq-oegzkg


https://wolfram.com/xid/0bdo2w6eq-uvst7f


https://wolfram.com/xid/0bdo2w6eq-fl1qha

Compare with the density function of a normal distribution:

https://wolfram.com/xid/0bdo2w6eq-blpftx


https://wolfram.com/xid/0bdo2w6eq-sx6z4n

Compute the expectation of an expression:

https://wolfram.com/xid/0bdo2w6eq-edmw6r


https://wolfram.com/xid/0bdo2w6eq-miucta

Skewness and kurtosis are constant:

https://wolfram.com/xid/0bdo2w6eq-xgr42o


https://wolfram.com/xid/0bdo2w6eq-bmnu2m


https://wolfram.com/xid/0bdo2w6eq-84cmmy


https://wolfram.com/xid/0bdo2w6eq-kupkj


https://wolfram.com/xid/0bdo2w6eq-6jz3hy

CentralMoment and its generating function:

https://wolfram.com/xid/0bdo2w6eq-eawm2x


https://wolfram.com/xid/0bdo2w6eq-j6j83y

FactorialMoment has no closed form for symbolic order:

https://wolfram.com/xid/0bdo2w6eq-o10xs2


https://wolfram.com/xid/0bdo2w6eq-qux587

Cumulant and its generating function:

https://wolfram.com/xid/0bdo2w6eq-fmfg53


https://wolfram.com/xid/0bdo2w6eq-sddn3s

Representations (5)
Approximate an AR process with an MA process of order 5:

https://wolfram.com/xid/0bdo2w6eq-e83icr

Compare the covariance function for the original and the approximate processes:

https://wolfram.com/xid/0bdo2w6eq-ej3a70


https://wolfram.com/xid/0bdo2w6eq-vs8skv

Approximate an ARMA process with an MA process:

https://wolfram.com/xid/0bdo2w6eq-2gxg6x


https://wolfram.com/xid/0bdo2w6eq-2l1314


https://wolfram.com/xid/0bdo2w6eq-lfz2ay

Approximate a SARIMA process with an MA process:

https://wolfram.com/xid/0bdo2w6eq-rai51r


https://wolfram.com/xid/0bdo2w6eq-2hnvxd

TransferFunctionModel representation:

https://wolfram.com/xid/0bdo2w6eq-hjt2st


https://wolfram.com/xid/0bdo2w6eq-7o8ehx

StateSpaceModel representation:

https://wolfram.com/xid/0bdo2w6eq-vee5af


https://wolfram.com/xid/0bdo2w6eq-15sscl

Applications (1)Sample problems that can be solved with this function
Consider the following time series data and determine whether it is adequately modeled by an MAProcess:

https://wolfram.com/xid/0bdo2w6eq-3rfo5c

https://wolfram.com/xid/0bdo2w6eq-ei2wi8

The correlation function drops off after lag 3. This is evidence of an MAProcess[3]:

https://wolfram.com/xid/0bdo2w6eq-dpjb4i

The partial correlation alternates and dampens slowly, which also indicates an MAProcess:

https://wolfram.com/xid/0bdo2w6eq-rd5h5

Fit an MAProcess[3] model to the data:

https://wolfram.com/xid/0bdo2w6eq-ewnell

Find residuals between the data and the model:

https://wolfram.com/xid/0bdo2w6eq-mg4jvd


https://wolfram.com/xid/0bdo2w6eq-lyqszg

https://wolfram.com/xid/0bdo2w6eq-1nbpys

Test if residuals are normal white noise:

https://wolfram.com/xid/0bdo2w6eq-dzmxsx


https://wolfram.com/xid/0bdo2w6eq-vizn9f

Properties & Relations (5)Properties of the function, and connections to other functions
MAProcess is a special case of an ARMAProcess:

https://wolfram.com/xid/0bdo2w6eq-4qu6v3


https://wolfram.com/xid/0bdo2w6eq-3e79y


https://wolfram.com/xid/0bdo2w6eq-towru5

MAProcess is a special case of an ARIMAProcess:

https://wolfram.com/xid/0bdo2w6eq-hf8lnw


https://wolfram.com/xid/0bdo2w6eq-13lrqo


https://wolfram.com/xid/0bdo2w6eq-rm66ol

MAProcess is a special case of a FARIMAProcess:

https://wolfram.com/xid/0bdo2w6eq-zgkahs


https://wolfram.com/xid/0bdo2w6eq-3367o3


https://wolfram.com/xid/0bdo2w6eq-h77nvk

MAProcess is a special case of a SARMAProcess:

https://wolfram.com/xid/0bdo2w6eq-vsue2k


https://wolfram.com/xid/0bdo2w6eq-5k3hsp


https://wolfram.com/xid/0bdo2w6eq-tl7p7z

MAProcess is a special case of a SARIMAProcess:

https://wolfram.com/xid/0bdo2w6eq-cq5j5v


https://wolfram.com/xid/0bdo2w6eq-hlalmx


https://wolfram.com/xid/0bdo2w6eq-lxav8k

Possible Issues (3)Common pitfalls and unexpected behavior
ToInvertibleTimeSeries does not always exist:

https://wolfram.com/xid/0bdo2w6eq-fqgvkc


There are zeros of the TransferFunctionModel on the unit circle:

https://wolfram.com/xid/0bdo2w6eq-u8o0e2


https://wolfram.com/xid/0bdo2w6eq-iro4yr

The method of moments may not find a solution in estimation:

https://wolfram.com/xid/0bdo2w6eq-joanlz

https://wolfram.com/xid/0bdo2w6eq-wxqglk



https://wolfram.com/xid/0bdo2w6eq-jg7rvl

Minimum prediction error estimation method does not allow repeated parameters:

https://wolfram.com/xid/0bdo2w6eq-p4xavf

https://wolfram.com/xid/0bdo2w6eq-n5vxq7



https://wolfram.com/xid/0bdo2w6eq-k46nya

Neat Examples (2)Surprising or curious use cases
Simulate a three-dimensional MAProcess:

https://wolfram.com/xid/0bdo2w6eq-d5vpru

https://wolfram.com/xid/0bdo2w6eq-1dkc1

Simulate paths from an MA process:

https://wolfram.com/xid/0bdo2w6eq-q7hoj9
Take a slice at 50 and visualize its distribution:

https://wolfram.com/xid/0bdo2w6eq-8s9gfo

https://wolfram.com/xid/0bdo2w6eq-g5fe1v
Plot paths and histogram distribution of the slice distribution at 50:

https://wolfram.com/xid/0bdo2w6eq-129cf

Wolfram Research (2012), MAProcess, Wolfram Language function, https://reference.wolfram.com/language/ref/MAProcess.html (updated 2014).
Text
Wolfram Research (2012), MAProcess, Wolfram Language function, https://reference.wolfram.com/language/ref/MAProcess.html (updated 2014).
Wolfram Research (2012), MAProcess, Wolfram Language function, https://reference.wolfram.com/language/ref/MAProcess.html (updated 2014).
CMS
Wolfram Language. 2012. "MAProcess." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2014. https://reference.wolfram.com/language/ref/MAProcess.html.
Wolfram Language. 2012. "MAProcess." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2014. https://reference.wolfram.com/language/ref/MAProcess.html.
APA
Wolfram Language. (2012). MAProcess. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/MAProcess.html
Wolfram Language. (2012). MAProcess. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/MAProcess.html
BibTeX
@misc{reference.wolfram_2025_maprocess, author="Wolfram Research", title="{MAProcess}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/MAProcess.html}", note=[Accessed: 02-June-2025
]}
BibLaTeX
@online{reference.wolfram_2025_maprocess, organization={Wolfram Research}, title={MAProcess}, year={2014}, url={https://reference.wolfram.com/language/ref/MAProcess.html}, note=[Accessed: 02-June-2025
]}