This function prepares data that have to be used.
prepareData(data=data,
restrictions=NULL,
eqlist=eqlist)An object of class prepareData, which is a list of the following elements:
list of the equations of the system,
number of the system equations,
list of the system variables,
number of the system coefficients,
position of the first variable of each equation, including the constant, in the ordered list of the variables of the system,
number of contraints,
a matrix with as many rows as constraints, and whose row elements indicate the position, in the sorted list of model variables, of the variables affected by each constraint,
total number of individuals,
total number of individuals observed in each period,
table reporting the number of times each individual is observed,
maximum number of times the individuals are observed in the panel,
number of period included in the panel,
sum of squares of the numbers of times each individual is observed,
sum of squares of the numbers of individuals observed in each time period,
vector containing the number of times each individual is observed,
subset of the original data frame containing only the variables used in the estimated system,
information on the sysdata dataframe obtained trougth the pdim command of the plm package.
a list containing the equations making up the SUR system. They should be object of the class "formula" and necessarly include the intercept,
a vector containing constraints on the equation coefficients, which should be expressed in the form "equation_name$variable_name". Any spaces should be excluded from the restrictions definition. If one of the constraints includes an intercept term, the variable_name will be simply 'const'. Only simple restrictions involving equality between two parameters are considered, and not linear combinations involving more than two parameters,
a data frame of the class "pdata.frame" (mandatory).