d Materials by Nicholas J. Cox, University of Durham d Nicholas J. Cox is a geographer at the University d of Durham and a frequent contributor to Statalist. His areas of interest d include graphics, smoothing, probability distributions, circular statistics, d and spatial and time series. p circstat Analysis of circular data p cpyxplot Scatter plots for each y vs. each x variable p egenodd Extensions to generate (various extras) p matodd Programs for various matrix tasks p tab_chi Tabulation and chi-square test programs p topichlp Help files on various general topics p univstat Summary statistics in matrix form