[R] Problem using RMySQL and fCalendar

Elizabeth Nichols betsy.nichols at plexlogic.com
Thu Mar 5 11:45:40 CET 2009

I am trying to use fCalendar for date arithmetic and the RMySQL package 
for accessing a MySQL database.   The fCalendar math operations seem to 
work fine UNTIL I load the RMySQL package.  Here is a demonstration:

ean at fibonacci:~/Desktop/amCharts/rsa-metrics$ R

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[Previously saved workspace restored]

 > library(fCalendar, pos=2)  # For date math
Loading required package: MASS
Loading required package: fUtilities
Rmetrics Package fUtilities (290.76) loaded.
Loading required package: fEcofin
Rmetrics Package fCalendar (270.78.2) loaded.
The new version of 'fCalendar' has been renamed to 'timeDate'
 > dt<-"1947-06-13"
 > myFC<-"America/NewYork"
 > DT<-timeDate(dt, zone=myFC, FinCenter=myFC)
 > DT + 3600
[1] [1947-06-13 01:00:00]
 > library(RMySQL, pos=4)     # For db access
 > DT + 3600
Error in `+.timeDate`(DT, 3600) :
 no slot of name "Data" for this object of class "timeDate"
In addition: Warning message:
In `+.timeDate`(DT, 3600) :
 trying to get slot "Data" from an object (class "timeDate") that is not 
an S4 object

As you can see, I can do date arithmetic (DT + 3600) before I load the 
RMySQL package but not after.  The "pos" arguments to the library() 
calls are an unsuccessful attempt to get R to use the Rmetrics fCalendar 
package that works instead of whatever gets loaded by RMySQL.

I have Googled until my fingers turned blue and I can't find any useful 
information to fix this.  Any help would be most appreciated.

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