quadFuncDeriv {micEcon} | R Documentation |
Calculate the derivatives of a quadratic function.
quadFuncDeriv( xNames, data, coef, coefCov = NULL, quadHalf = TRUE )
xNames |
a vector of strings containing the names of the independent variables. |
data |
dataframe containing the data. |
coef |
vector containing all coefficients. |
coefCov |
optional covariance matrix of the coefficients. |
quadHalf |
logical. Multiply the quadratic terms by one half? |
a list of class quadFuncDeriv
containing following objects:
deriv |
data frame containing the derivatives. |
variance |
data frame containing the variances of the derivatives
(only if argument coefCov is provided). |
stdDev |
data frame containing the standard deviations of the derivatives
(only if argument coefCov is provided). |
Arne Henningsen ahenningsen@agric-econ.uni-kiel.de
data( germanFarms ) # output quantity: germanFarms$qOutput <- germanFarms$vOutput / germanFarms$pOutput # quantity of variable inputs germanFarms$qVarInput <- germanFarms$vVarInput / germanFarms$pVarInput # a time trend to account for technical progress: germanFarms$time <- c(1:20) # estimate a quadratic production function estResult <- quadFuncEst( "qOutput", c( "qLabor", "land", "qVarInput", "time" ), germanFarms ) # compute the marginal products of the inputs margProducts <- quadFuncDeriv( c( "qLabor", "land", "qVarInput", "time" ), germanFarms, coef( estResult ), vcov( estResult ) ) margProducts$deriv