January 8, 2014
Bill Sacks

The following documents the steps used to create the test dataset,
surfdata.pftdyn_1x1_tropicAtl_TEST_simyr1939-1943_c140108.nc. As the name
implies, this dataset is based off of
surfdata.pftdyn_1x1_tropicAtl_hist_simyr1850-2005_c130627.nc, but contains just
a subset of years. The purpose is to test some edge cases of reading the
transient PFT dataset.

I started by taking a subset of the years from the original dataset. However, I
then modified the PCT_NAT_PFT array so that each year has a unique breakdown
into PCT_NAT_PFT - to catch any problems with reading in the wrong year of data.

Here were the specific steps:

ncks -d time,89,93 surfdata.pftdyn_1x1_tropicAtl_hist_simyr1850-2005_c130627.nc surfdata.pftdyn_1x1_tropicAtl_TEST_simyr1939-1943_c140108.nc

From R:
> dat.subset <- read.ncdf('surfdata.pftdyn_1x1_tropicAtl_TEST_simyr1939-1943_c140108.nc')
> for (time in 2:5) {
+ dat.subset$PCT_NAT_PFT$data[5,time] <- dat.subset$PCT_NAT_PFT$data[5,time] - time
+ dat.subset$PCT_NAT_PFT$data[16,time] <- dat.subset$PCT_NAT_PFT$data[16,time] + time
+ }
> write.ncdf('new.pct_nat_pft.nc', dat.subset)

ncks -A -v PCT_NAT_PFT new.pct_nat_pft.nc surfdata.pftdyn_1x1_tropicAtl_TEST_simyr1939-1943_c140108.nc