dealloc — Deallocate Structures

Deallocates all allocatable arrays within an FPL data structure, releasing memory.

Usage

call dealloc(idata)

Parameter	Type	Description
idata	FPL type	Structure to deallocate

Behavior

Deallocates the following arrays if allocated:

• ncdata — main data array
• longitudes — longitude coordinates
• latitudes — latitude coordinates
• times — time coordinates (3D/4D types)
• levels — level coordinates (4D types)
• dimname, dimunits — dimension metadata
• dimid, dimsize, varids — internal NetCDF IDs

caution

Always call dealloc before reusing or discarding an FPL structure. Failing to deallocate causes memory leaks, which accumulate quickly when processing large geospatial datasets.

Code Example

Filter soybean data by state and deallocate between iterations:

program main
  use fpl
  implicit none

  type(nc3d_float_llf_ti) :: soybean
  type(nc2d_byte_llf)     :: states

  integer(kind=intgr) :: s
  character(200) :: ipath_soybean, ipath_states, opath

  ipath_soybean = "database/soybean_production.nc"
  ipath_states  = "database/states.nc"

  ! Read soybean and states data
  call readgrid(ipath_soybean, soybean)
  call readgrid(ipath_states, states)

  ! Filter production per state (1 to 27)
  do s = 1, 27
    ! Set FillValue for the current state code
    states%FillValue = int(s, kind=byte)

    ! Mask soybean where state != s
    call setfillvalue(soybean, states)

    ! Write filtered output
    write(opath, '(A,I2.2,A)') "database/soybean_state_", s, ".nc"
    call writegrid(opath, soybean)

    ! Deallocate and re-read for next state
    call dealloc(soybean)
    call dealloc(states)

    call readgrid(ipath_soybean, soybean)
    call readgrid(ipath_states, states)
  end do

  call dealloc(soybean)
  call dealloc(states)
end program main

Compile & Run

gfortran -o dealloc.out dealloc.f90 -I/usr/lib64/gfortran/modules/ -lFPL
./dealloc.out