Fun with GLM links

I can never keep this straight: When to use link(log) vs. link(logit) in generalized linear models:

Use link(log) when you are after relative risks.
Use link(logit) when you are after odds ratios.

Simple vector analysis in R

First, create a vector:

ClassGrades<- c(94, 95, 91)
#defines a vector called "ClassGrades" by concatenating individual grades on the exam

Then, run your simple analysis

mean(ClassGrades)
#returns the mean on the exam

hist(GlassGrades)
#produces a histogram of the exam grades

ArcGIS fields: What's the difference between "address" and "ARC_Street"?

From Getting to Know ArcGIS Desktop, Ormsby et al:

"When you rematch unmatched addresses, you can edit the values in ARC_Street and ARC_Zone to make matches. You would do this, for example, if you found mistakes in the (original data) table. The ADDRESS and ZIP attributes, on the other hand, preserves the original information from the (original data) table."

R vocab

From R Tutuorial

A note on data terminology:
"A vector is a sequence of data elements of the same basic type. Members in a vector are officially called components. Nevertheless, we will just call them members in this site."