Skip to content

Overview of structural model objects

Structural models are systems of dynamic simultaneous (interdependent) equations with lags and leads (expectations). Iris supports nonlinear nonstationary (balanced growth path) structural models.

Categorical list of functions

Constructing model objects

Function Description
Model.fromFile Create new Model object from model source file(s)
Model.fromSnippet Create new Model object from snippet of code within m-file
Model.fromString Create new Model object from string array

Getting information about models

Function Description
access Access properties of Model objects
beenSolved True if first-order solution has been successfully calculated
byAttributes Look up model quantities and equation by attributes
findEquation Find equations whose input strings pass one or more tests
getBounds Get lower and upper bounds imposed on model quantities
isLinear True if the model has been declared as linear
isLinkActive True if dynamic link is active
isLog True for variables declared as log-variables
print Print model object
solutionMatrices Access first-order state-space (solution) matrices
subsref Subscripted reference for Model objects
table Create table based on selected indicators from Model object
isnan Check for NaNs in model object.
isempty True for empty model object

Assigning values within models

Function Description
assign Assign parameters, steady states, std deviations or cross-correlations
assignFromModel Assign model quantities from another model
replaceNames Replace model names with some other names
reset Reset specific values within model object
resetBounds Reset lower and upper bounds imposed on model quantities
setBounds Set bounds for model quantities
rescaleStd Rescale all std deviations by the same factor

Analytical properties of models

Function Description
analyticGradients Evaluate analytic/symbolic derivatives of model equations
blazer Analyze sequential block structure of steady equations
eig Eigenvalues of model transition matrix
systemMatrices First-order system matrices describing the unsolved model
isstationary True if the model or a linear combination of its variables is stationary

Stochastic properties of models

Function Description
acf Autocovariance and autocorrelation function for model variables
fevd Forecast error variance decomposition for model variables.
ffrf Filter frequency response function of transition variables to measurement variables
fisher Approximate Fisher information matrix in frequency domain
fmse Forecast mean square error matrices.

Solving and simulating models

Function Description
checkSteady Check if equations hold for currently assigned steady-state values
checkInitials Check if databank contains all initial conditions for simulation
expand Compute forward expansion of model solution for anticipated shocks
simulate Run a model simulation
solve Calculate first-order solution matrices
steady Compute steady state or balance-growth path of the model
system System matrices for the unsolved model
lhsmrhs Discrepancy between the LHS and RHS of each model equation for given data

Estimating and filtering model quantities

Function Description
beveridgeNelson Beveridge-Nelson trends
estimate.md Estimate model parameters by maximizing posterior-based objective function
kalmanFilter Kalman smoother and estimator of out-of-likelihood parameters

Manipulating the structure of models

Function Description
activeLink Activate dynamic links for selected LHS names
deactiveLink Deactivate dynamic links for selected LHS names
alter Expand or reduce number of parameter variants in model object
changeGrowthStatus Change growth status of the model
changeLinearStatus Change linear status of model
changeLogStatus Change log status of model variables
horzcat Merge two or more compatible model objects into multiple parameterizations