What's New in May, 2009?

General

• FAQ: How do I interpret the sign of the quadratic term in a polynomial regression?

R

• Code Fragment: How can I read multiple files into R?

SAS

• Code Fragment: Summary table for multiple regression models
• FAQ: How can I export my SAS results to an Excel spreadsheet?
• FAQ: How can I send SAS data/results to specific cells in an Excel spreadsheet?
• FAQ: How can I do path analysis in SAS?
• Code Fragment: Summary table for logistic regression models
• FAQ: How can I include cells with zero counts in proc freq with the list option?

SPSS

• FAQ: How can I convert string variables data into date variables?
• Code Fragment: Looping with dates
• FAQ: How can SPSS help me document my data?

Stata

• FAQ: How can I convert a multilevel model to a mixed model?
• FAQ: How can I access information stored after I run a command in Stata (returned results)?
• FAQ: How can I graph chi-square power curves in Stata?
• Code Fragment: Fitting a seemingly unrelated regression (sureg) manually
• FAQ: How can I reshape doubly (or triply) wide data to long?
• FAQ: How can I fit a random intercept or mixed effects model with heteroskedastic errors?