Possible memory leak in Ferret v5.6

["Gustafson, William I" <william.gustafson@xxxxxxx>]

Dear Ferreters,

Have any of you had problems with a memory leak in Ferret when using it with data pulled from a Grads-DODS servers? Below is a simple script I wrote to download data from the nomads server at NCDC. I loops through all the days of a given month and then writes the data from one variable to a file. I have noticed that every time one of the daily files is closed and another opened, Ferret sucks up another ~4Mb of memory. I have tried adding a "cancel memory/all" command inside the repeat loop, but this does not seem to help. When downloading one month of data, this problem is annoying but not detrimental. However, when I use a similar technique to get a year's worth of data, Ferret works its way up to 1.25+ Gb and I have to start swapping a lot, which slows everything on the machine down.

Thanks for any help.

-Bill



!-----------------------------------------------------------------------
! Script to download North American Regional Reanalysis data from the
! NCDC GDS server. It is assumed that no other data files are open.
!
! Author: William.Gustafson@pnl.gov; 7-Oct-2004
!-----------------------------------------------------------------------

!-----------------------------------------------------------------------
! User settings...
!-----------------------------------------------------------------------
define symbol var = apcp

define symbol yr  = 1994
define symbol mn  = 12

define symbol dys = 1
define symbol dye = 31

!-----------------------------------------------------------------------
! Here we go...
!-----------------------------------------------------------------------

!Chop off the portions of the globe with all missing data
set region/x=-212:-4/y=-10:86

let month = if ($mn) lt 10 then "0($mn)" else "($mn)"; \
repeat/name=dy/range=($dys):($dye) ( \
   let day = if `dy` lt 10 then "0`dy`" else "`dy`"; \
   cancel memory/all; \
   set data "http://nomads.ncdc.noaa.gov:9091/dods/NCEP_NARR_DAILY/($yr)`month`/($yr)`month``day`/narr-a_221_($yr)`month``day`_0000_000"; \
   list/form=cdf/file="($var).nc"/append ($var)[l=1:8]; \
   cancel data 1; \
)

_______________________________________
William I. Gustafson Jr., Ph.D.
Pacific Northwest National Laboratory
P.O. Box 999, MSIN K9-30
Richland, WA 99352, USA
Voice & Msg: (509)372-6110
FAX: (509)372-6168
http://www.pnl.gov/atmos_sciences