library("mlt") library("mlt.docreg") library("truncreg") ### make M1mac happy options(digits = 4) ## Left-truncated set.seed(29) n <- 1000 x <- runif(n, max = 2 * pi) y <- rnorm(n, 2*x + 1, .25) d <- data.frame(y = y, x = x) ## truncated response tr <- 2.5 d$yt <- ifelse(d$y > tr, d$y, NA) d$trunc_left <- tr tmod <- truncreg(yt ~ x, data = d, point = tr, direction = "left") coef(tmod) logLik(tmod) vcov(tmod) ## MLT fm <- as.formula("~ x") yb <- polynomial_basis(numeric_var("yt", support = range(d$yt, na.rm = TRUE)), coef = c(TRUE, TRUE), ci = c(-Inf, 0)) m <- ctm(yb, shifting = fm, todistr = "Normal", data = d) dfull <- d[!is.na(d$yt),,drop = FALSE] dfull$yt <- R(dfull$yt, tleft = dfull$trunc_left) mltmod <- mlt(m, data = dfull) (cf <- coef(mltmod)) c(-cf[1] / cf[2], -cf[3] / cf[2], 1 / cf[2]) logLik(mltmod) vcov(mltmod) checkGH(mltmod) ## right-truncated set.seed(29) n <- 1000 x <- runif(n, max = 2 * pi) y <- rnorm(n, 2*x + 1, .25) d <- data.frame(y = y, x = x) ## truncated response tr <- 11 d$yt <- ifelse(d$y < tr, d$y, NA) d$trunc_right <- tr tmod <- truncreg(yt ~ x, data = d, point = tr, direction = "right") coef(tmod) logLik(tmod) vcov(tmod) ## MLT fm <- as.formula("~ x") yb <- polynomial_basis(numeric_var("yt", support = range(d$yt, na.rm = TRUE)), coef = c(TRUE, TRUE), ci = c(-Inf, 0)) m <- ctm(yb, shifting = fm, todistr = "Normal", data = d) dfull <- d[!is.na(d$yt),,drop = FALSE] dfull$yt <- R(dfull$yt, tright = dfull$trunc_right) mltmod <- mlt(m, data = dfull) (cf <- coef(mltmod)) c(-cf[1] / cf[2], -cf[3] / cf[2], 1 / cf[2]) logLik(mltmod) vcov(mltmod) checkGH(mltmod)