[R] MultiDimensional arrays

[Steve_Friedman at nps.gov]

hello,

I'm working with a 4 dimensional NetCDF file, trying to calculate some
summary statistics on a parameter.

The dimensions are number of rows and columns, time and days.  The
attribute in question in this case happens
to be a probability of woodstork foraging success. But it could be anything

My question is whether the following code is efficient to grab the
probability values ?  I am not skilled with multidimensional arrays, the
code below was written for by a highly skilled Java coder, who does not
know R.

Any suggestions would be greatly appreciated.

Thanks
Steve

Working with a Windows XP machine and R 2.12.1


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library(tis)     #  includes function for leap year
library(ncdf)

library(fields)  links to an animation routine not shown

woodstorks <- open.ncdf("WoodStork_Eden_2000_2009.nc")

 v2 <- woodstorks$var[[2]]    # longname
"probability_of_successful_foraging_cycle_daily"

 DaysToMonth365 <- c(0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334,
365)
 DaysToMonth366 <- c(0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335,
366)

 Lyear <- isLeapYear(2000:2009) #  returns boolean vector TRUE FALSE for
years in sequence

start_year<- 1999    #  we process 11 years with 265 daily data records in
a 287 x 405 row x column map.
   for(t in 1:11) {
   currentYear = start_year + t
   leapYear <- isLeapYear(currentYear:currentYear) #  returns boolean
vector TRUE FALSE for years in sequence
   #print(leapYear)
    Days<-DaysToMonth365
          if(leapYear){
             Days<-DaysToMonth366
           }
      #print(Days)
      data <- array(data, dim = c(Days[1], 405, 265))
         for(d in 1: 226) {
               for(y in 1: 405) {
                 for(x in 1:287) {
                      day = 1
                      counter <- 2  # first element in array
                    #print(paste("day = ", d))
                   if(d >= Days[counter]) {
                       counter <- counter + 1
                       #print(paste("here = ", t))
                       processMonth(data)       #  function defined outside
of this command sequence
                       data <- array(data, dim = c(Days[1], 405, 265))
                        day = 1
                     }
                       else
                   {
                   index<-c(x,y,d,t)
                   count<-c(1,1,1,1)
                   temp<-  get.var.ncdf(woodstorks, v2, start=index, count
= count)
                   i <- (d*405*287) + (y*287) + x #map 3d to 1dimension
                   data[i] = temp[1]
                   #print(data[i])
                   day <- day + 1
                  }
               }
           }
         }
      }




Steve Friedman Ph. D.
Ecologist  / Spatial Statistical Analyst
Everglades and Dry Tortugas National Park
950 N Krome Ave (3rd Floor)
Homestead, Florida 33034

Steve_Friedman at nps.gov
Office (305) 224 - 4282
Fax     (305) 224 - 4147