Grid/
computegrid.pro
compute the grid parameters (cm_4mesh) common
domains sizes:
---------------
jpi, jpj, jpk, jpiglo, jpjglo, jpkglo, jpidta, jpjdta, jpkdta
domains positions regarding to the original grid:
--------------------------------------------------
ixminmesh, ixmaxmesh, iyminmesh, iymaxmesh, izminmesh, izmaxmesh
ixmindta, ixmaxdta, iymindta, iymaxdta, izmindta, izmaxdta
horizontal parameters:
----------------------
glamt, glamf, gphit, gphit, e1t, e2t
additional horizontal parameters if FULLCGRID keyword is defined:
-----------------------------------------------------------------
glamu, glamv, gphiu, gphiv, e1u, e1v, e1f, e2u, e2v, e2f
verticals parameters:
---------------------
gdept, gdepw, e3t, e3w
masks:
------
tmask
additional masks if FULLCGRID keyword is defined:
-------------------------------------------------
umaskred, vmaskred, fmaskredx, fmaskredy
triangles_list:
---------------
triangulation
key_* variables:
----------------
key_onearth, key_periodic, key_shift, key_stride, key_partialstep,
key_yreverse, key_zreverse, key_gridtype
xxx related variables:
----------------------
ccmeshparameters, ccreadparameters
computegrid
Grid
computegrid[, startx][, starty][, stepxin][, stepyin][, nxin][, nyin], XAXIS=1D or 2D array, YAXIS=1D or 2D array, ZAXIS=1D, MASK=2D or 3D array, GLAMBOUNDARY=2 elements vector, XMINMESH=scalar, XMAXMESH=scalar, YMINMESH=scalar, YMAXMESH=scalar, ZMINMESH=scalar, ZMAXMESH=scalar, ONEARTH=scalar: 0 or 1, PERIODIC=scalar: 0 or 1, PLAIN=scalar: 0 or 1, SHIFT=scalar, STRIDE=3 elements vector, FULLCGRID=scalar: 0 or 1, XYINDEX=XYINDEX, UBASE2TBASE=UBASE2TBASE, VBASE2TBASE=VBASE2TBASE, FBASE2TBASE=FBASE2TBASE, STRCALLING=scalar string, ROMSH=2D array, _extra=_extra
Parameters
startx
in
optional
type: scalar
x starting point, optional if [XY]AXIS keyword is used
starty
in
optional
type: scalar
y starting point, optional if [XY]AXIS keyword is used
stepxin
in
optional
type: scalar or vector
x direction step, optional if [XY]AXIS keyword is used, must be > 0
if stepxin is a vector nx is not used
stepyin
in
optional
type: scalar or vector
y direction step, optional if [XY]AXIS keyword is used,
could be > 0 (south to north) or < 0 (north to south)
if stepyin is a vector ny is not used
nxin
in
optional
type: scalar
number of points in x direction,
optional if [XY]AXIS keyword is used or stepxin is a vector
nyin
in
optional
type: scalar
number of points in y direction,
optional if [XY]AXIS keyword is used or stepyin is a vector
Keywords
XAXIS
type: 1D or 2D array
Specify longitudes in this case startx, stepx and nx are not used but
could be necessary if the y axis is not defined with yaxis. It must be
possible to sort the first line of xaxis in the increasing order by
shifting its elements.
YAXIS
type: 1D or 2D array
Specify latitudes in this case starty, stepy and ny are not used but
starty and stepy could be necessary if the x axis is not defined with
xaxis. It must be sorted in the increasing or deceasing order (along each column if 2d array).
ZAXIS
type: 1D
Specify the vertical axis. Must be sorted in the increasing or deceasing order
MASK
type: 2D or 3D array
default: array of 1
Specify the land(0)/sea(1) mask
GLAMBOUNDARY
type: 2 elements vector
default: those defined in the file
Longitude boundaries that should be used to visualize the data.
lon2 > lon1
lon2 - lon1 le 360
By default, the common (cm_4mesh) variable key_shift will be automatically
defined according to GLAMBOUNDARY.
XMINMESH
type: scalar
default: 0L
Define common (cm_4mesh) variables ixminmesh used to define the localization
of the first point of the grid along the x direction in a zoom of the original grid
XMAXMESH
type: scalar
default: jpiglo-1
Define common (cm_4mesh) variables ixmaxmesh used to define the localization
of the last point of the grid along the x direction in a zoom of the original grid
Note that if XMAXMESH < 0 then ixmaxmesh is defined as ixmaxmesh = jpiglo -1 + xmaxmesh
YMINMESH
type: scalar
default: 0L
Define common (cm_4mesh) variables iyminmesh used to define the localization
of the first point of the grid along the y direction in a zoom of the original grid
YMAXMESH
type: scalar
default: jpjglo-1
Define common (cm_4mesh) variables iymaxmesh used to define the localization
of the last point of the grid along the y direction in a zoom of the original grid
Note that if YMAXMESH < 0 then iymaxmesh is defined as iymaxmesh = jpjglo -1 + ymaxmesh
ZMINMESH
type: scalar
default: 0L
Define common (cm_4mesh) variables izminmesh used to define the localization
of the first point of the grid along the z direction in a zoom of the original grid
ZMAXMESH
type: scalar
default: jpkglo-1
Define common (cm_4mesh) variables izmaxmesh used to define the localization
of the last point of the grid along the z direction in a zoom of the original grid
Note that if ZMAXMESH < 0 then izmaxmesh is defined as izmaxmesh = jpkglo -1 + maxmesh
ONEARTH
type: scalar: 0 or 1
default: 1
Force the manual definition of data localization on the earth or not
0) if the data are not on the earth
1) if the data are on earth (in that case we can for example use
the labels 'longitude', 'latitude' in plots).
The resulting value will be stored in the common (cm_4mesh) variable key_onearth
ONEARTH = 0 forces PERIODIC = 0, SHIFT = 0 and is cancelling GLAMBOUNDARY
PERIODIC
type: scalar: 0 or 1
default: computed by using the first line of glamt
Force the manual definition of the grid zonal periodicity.
The resulting value will be stored in the common (cm_4mesh) variable key_periodic
PERIODIC = 0 forces SHIFT = 0
PLAIN
type: scalar: 0 or 1
default: 0
Force PERIODIC = 0, SHIFT = 0, STRIDE = [1, 1, 1] and
suppress the automatic redefinition of the domain in case of
x periodicity overlap, y periodicity overlap (ORCA type only)
and mask border to 0.
SHIFT
type: scalar
default: computed according to glamboundary
Force the manual definition of the zonal shift that must be apply to the data.
The resulting value will be stored in the common (cm_4mesh) variable key_shift
Note that if key_periodic=0 then in any case key_shift = 0.
STRIDE
type: 3 elements vector
default: [1, 1, 1]
Specify the stride in x, y and z direction. The resulting
value will be stored in the common (cm_4mesh) variable key_stride
FULLCGRID
type: scalar: 0 or 1
default: 0
Activate to specify that you want to compute all the C grid parameters:
definition of glam[uv], gphi[uv], e1[uvf], e2[uvf], [uv]maskred and
fmaskred[xy] will be add to the default computations
XYINDEX
activate to specify that the horizontal grid should
be simply defined by using the index of the points
(xaxis = findgen(nx) and yaxis = findgen(ny))
using this keyword forces key_onearth=0
UBASE2TBASE
Activate when the model is a C grid based on a U point
(with a U point at the bottom-left corner and a T point at the
upper-right corner). In this case, we ignore
- if the grid is not x-periodic, the first column of F and U points
- if the grid is not x-periodic, the last column of T and V points.
=> we are back to a C grid based on T point as for OPA model.
Note that in that case, key_gridtype = 'c_u' and not 'c' (-> used in read_ncdf)
Note that activate UBASE2TBASE forces FULLCGRID=1
VBASE2TBASE
Activate when the model is a C grid based on a V point
(with a V point at the bottom-left corner and a T point at the
upper-right corner). In this case, we ignore
- the first line of F and V points
- the last line of T and U points
=> we are back to a C grid based on T point as for OPA model.
Note that in that case, key_gridtype = 'c_v' and not 'c' (-> used in read_ncdf)
Note that activate VBASE2TBASE forces FULLCGRID=1
FBASE2TBASE
Activate when the model is a C grid based on a F point
(with a F point at the bottom-left corner and a T point at the
upper-right corner). In this case, we ignore
- the first line of F and V points
- the last line of T and U points
- if the grid is not x-periodic, the first column of F and U points
- if the grid is not x-periodic, the last column of T and V points.
=> we are back to a C grid based on T point as for OPA model.
Note that in that case, key_gridtype = 'c_f' and not 'c' (-> used in read_ncdf)
Note that activate FBASE2TBASE forces FULLCGRID=1
STRCALLING
type: scalar string
a string containing the calling command used to
call computegrid (this is used by xxx.pro)
Used by xxx...
ROMSH
type: 2D array
This array is the final bathymetry at RHO-points. It is stored in the common
variable (cm_4mesh) romszinfos.h
Used when the model is a ROMS C-grid with one more point
in longitude for T and V grid and one more point in latitude
for T and U grid. In this case, we ignore
- the last line of T and U points
- the last column of T and V points.
=> we are back to a C grid based on T point as for OPA model.
Note that activate ROMSH forces FULLCGRID=1
_extra
(not used in the present case...)
Version history
Version
$Id: computegrid.pro 213 2007-02-16 11:29:17Z smasson $
History
Sebastien Masson (smasson@lodyc.jussieu.fr)
2000-04-20
Sept 2004, several bug fixs to suit C grid type...
Aug 2005, rewritte almost everything...
Known issues
Restrictions
if the grid has x/y periodicity orverlap and/or if
the mask has 0 everywhere at the border (like a close sea) and
if (we did not activate /plain and xminmesh, xmaxmesh, yminmesh,
ymaxmesh keywords are defined to their default values), we redefine
xminmesh, xmaxmesh, yminmesh, ymaxmesh in order to reove the
overlapping part and/or to open the domain (avoid ti be forced
to use cell_fill = 1).
FUV points definition is not exact if the grid is irregular
Other attributes
Uses routines
cm_4mesh cm_4data cm_4cal
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