formula: formula for restricted MIDAS regression or midas_r object. Formula must include fmls function
data: a named list containing data with mixed frequencies
start: the starting values for optimisation. Must be a list with named elements.
Ofunction: the list with information which R function to use for optimisation. The list must have element named Ofunction which contains character string of chosen R function. Other elements of the list are the arguments passed to this function. The default optimisation function is optim with arguments method="Nelder-Mead" and control=list(maxit=5000). Other supported functions are nls, optimx.
...: additional arguments supplied to optimisation function
Returns
a midas_r object which is the list with the following elements:
coefficients: the estimates of parameters of restrictions
midas_coefficients: the estimates of MIDAS coefficients of MIDAS regression
model: model data
unrestricted: unrestricted regression estimated using midas_u
term_info: the named list. Each element is a list with the information about the term, such as its frequency, function for weights, gradient function of weights, etc.
fn0: optimisation function for non-linear least squares problem solved in restricted MIDAS regression
rhs: the function which evaluates the right-hand side of the MIDAS regression
gen_midas_coef: the function which generates the MIDAS coefficients of MIDAS regression
opt: the output of optimisation procedure
argmap_opt: the list containing the name of optimisation function together with arguments for optimisation function
start_opt: the starting values used in optimisation
start_list: the starting values as a list
call: the call to the function
terms: terms object
gradient: gradient of NLS objective function
hessian: hessian of NLS objective function
gradD: gradient function of MIDAS weight functions
Zenv: the environment in which data is placed
nobs: the number of effective observations
convergence: the convergence message
fitted.values: the fitted values of MIDAS regression
Such model is a generalisation of so called ADL-MIDAS regression. It is not required that all the coefficients should be restricted, i.e the function g(i)
might be an identity function. Model with no restrictions is called U-MIDAS model. The regressors xτ(i) must be of higher (or of the same) frequency as the dependent variable yt.