[R] Surface plot for polynomial regression

2005-03-31 Thread Johannes Ullrich
in the quadratic fit of scatter3d. Any pointers would be welcome. I should add that I am not a programmer and mainly work with high-level functions. Thank you very much for R and for your help Johannes Dipl.-Psych. Johannes Ullrich Philipps-Universität Marburg

[R] Scaled or unscaled variance covariance matrix

2006-03-16 Thread Johannes Ullrich
.-Psych. Johannes Ullrich Philipps-Universität Marburg Fachbereich Psychologie AG Sozialpsychologie 35037 Marburg Germany T. ++49 6421 / 2823654 F. ++49

[R] adding mean to boxplot

2004-01-22 Thread Johannes Ullrich
I am a new and unexperienced user of R and got so far as to know how to produce boxplots. I have no experience of messing with function code, so presently I do not know how to create a boxplot with group means instead of group medians. If somebody could help me either replace the median with