Rosepack Document 1: Guidelines for Writing Semi-portable Fortran

Transferring Fortran subroutines from one manufacturer's machine to another or from one operating system to another puts certain constrains on the construction of the Fortran statements that are used in the subroutines. The reliable performance of this mathematical software should be unaffected by the host environment in which the software is used or by the compiler from which the code is generated. In short, the algorithm is to he independent of the computing environment in which it is run. The subroutines of ROSEPACK (Robust Statistics Estimation Package) are Fortran IV source code designed to be semi-portable where semi-portable is defined to mean transportable with minimum change.*

The Singular Value Analysis in Matrix Computation

This paper discusses the robustness and the computational stability of the singular value decomposition algorithm used at the NBER Computer Research Center. The effect of perturbations on input data is explored. Suggestions are made for using the algorithm to get information about the rank of a real square or rectangular matrix. The algorithm can also be used to compute the best approximate solution of linear system of equations in the least squares sense, to solve linear systems of equations with equality constraints, and to determine dependencies or near dependencies among the rows or columns of a matrix. A copy of the subroutine that is used and some examples on which it has been tested are included in the appendixes.

A System of Subroutines For Iteratively Reweighted Least Squares Computations

A description of a system of subroutines to compute solutions to the iteratively reweighted least squares problem is presented. The weights are determined from the data and linear fit and are computed as functions of the scaled residuals. Iteratively reweighted least squares is a part of robust statistics where "robustness" means relative insensitivity to moderate departures from assumptions. The software for iteratively reweighted least squares is cast as semi-portable Fortran code whose performance is unaffected (in the sense that performance will not be degraded) by the computer or operating-system environment in which it is used. An [ell sub1] start and an [ell sub2] start are provided. Eight weight functions, a numerical rank determination, convergence criterion, and a stem-and-leaf display are included.

Establishing a Core Outcome Measure for Fatigue in Patients on Hemodialysis: A Standardized Outcomes in Nephrology–Hemodialysis (SONG-HD) Consensus Workshop Report

Fatigue is one of the most highly prioritized outcomes for patients and clinicians, but remains infrequently and inconsistently reported across trials in hemodialysis. We convened an international Standardized Outcomes in Nephrology–Hemodialysis (SONG-HD) consensus workshop with stakeholders to discuss the development and implementation of a core outcome measure for fatigue. 15 patients/caregivers and 42 health professionals (clinicians, researchers, policy makers, and industry representatives) from 9 countries participated in breakout discussions. Transcripts were analyzed thematically. 4 themes for a core outcome measure emerged. Drawing attention to a distinct and all-encompassing symptom was explicitly recognizing fatigue as a multifaceted symptom unique to hemodialysis. Emphasizing the pervasive impact of fatigue on life participation justified the focus on how fatigue severely impaired the patient’s ability to do usual activities. Ensuring relevance and accuracy in measuring fatigue would facilitate shared decision making about treatment. Minimizing burden of administration meant avoiding the cognitive burden, additional time, and resources required to use the measure. A core outcome measure that is simple, is short, and includes a focus on the severity of the impact of fatigue on life participation may facilitate consistent and meaningful measurement of fatigue in all trials to inform decision making and care of patients receiving hemodialysis