Monthly Archives: July 2012

Converting timestamps in PostgreSQL (again)

Revisited converting timestamps to UTC from different timezones. One way to do this is a variation on the PostgreSQL documentation on date/time functions, where epoch is used as a common unit: Gets the job done, but the following is cleaner: … Continue reading

Posted in PostgreSQL | Tagged , ,

Dolphin!

Pic of a Bottlenose dolphin (Tursiops truncatus) breaching during cooperative hunting activity; May River, Beaufort County, South Carolina. Amazing.

Posted in coastal ecology, marine biology, marine ecology | Tagged , , , , , ,

From a long to a wide R data frame, with array values

From a “long” data frame with columns containing the names of measured properties and corresponding vectors of values, attempting to make a “wide” data frame with a column for each measured property. Appears as though the cast() function of the reshape … Continue reading

Posted in data munging, R | Tagged , , , , ,

Storing numeric vectors (or arrays) in fields of an R data frame

To store variable-length data vectors and corresponding single-value data in separate fields of the same row of an R data frame, add a new modeless column then populate it: R recognizes that the vector’s class is numeric, but it is necessary … Continue reading

Posted in data munging, R | Tagged , , , ,

Quick-and-dirty coastal habitat characterization, part 4: Salt marshes

Fourth and final post on coastal habitat characterization for the Northwest Atlantic: salt marshes. Provides a starting point for a more detailed narrative and application of modifiers. All factors used here are after Knox (2001) and Bertness (2007): 1) Marsh maturity young … Continue reading

Posted in coastal ecology, habitat characterization, marine ecology, salt marshes, western atlantic

rgdal on Mac OS X: reprise

After successful installation of rgdal on a Mac, trying again on an older MacBook Pro running OS X 10.5 (Leopard). Upgraded to the latest R (2.13.1), and followed all of my previous steps. But on “R CMD INSTALL…” got an … Continue reading

Posted in os x, packages, R

Quick-and-dirty coastal habitat characterization, part 3: Man-made structures

Apart from artificial reefs, could not find substantive information on other types of infrastructure in general texts on coastal ecology; so for this post relying on a recent review paper, and the perspectives of contributers to Sea Grant databases. Characterization … Continue reading

Posted in coastal ecology, habitat characterization, man-made structures, marine ecology, western atlantic