The smtwice ado-file for a nonlinear resistant smoother presented in sed7 (Salgado-Ugarte and García 1992) is included on the STB diskette. A new version of the ado-file sm4253eh for Stata 3.0 has been prepared and may be installed in place of the former, which was for Stata 2.1. This new version has a more efficient algorithm for carrying out running medians of span 5 and permits the keeping of the original values of the sequence. In this way the results (generated as new variables by the program) are the smoothed values and a time index. It is now possible to build a graph with the original and smoothed values for camparison after smoothing.
