GRATGRID

Name	Type	Caption	Length	Value range
FILI *	str	Input file name	1 -
FILO	str	Output vector file name	0 -
DBVS	List[int]	Input vector segment or layer	0 - 1
DBSN	str	Output vector layer name	0 - 8
DBSD	str	Output vector layer description	0 - 64
LAYERTYPE	str	Layer type	0 - 8	Lines \| Points \| Polygons Default: Lines
GRIDTYPE	str	Grid type	0 - 10	Geocoded \| Geographic Default: Geocoded
MAPUNITS	str	Map units	0 - 17	Default: METER
LLBOUNDS	str	Output bounds are in logitude and latitude	0 - 3	YES \| NO Default: NO
ULX	str	Upper-left X coordinate	0 - 64
ULY	str	Upper-left Y coordinate	0 - 64
LRX	str	Lower-right X coordinate	0 - 64
LRY	str	Lower-right Y coordinate	0 - 64
XINCRE *	List[float]	X increment	1 - 1	1.0 -
YINCRE *	List[float]	Y increment	1 - 1	1.0 -

Parameter descriptions

FILI

Specifies the name of the PCIDSK file containing the georeferencing information to use in the new graticule/grid layer.

FILO

Specifies the name of the PCIDSK file to receive the output graticule/grid layer. If this parameter is not specified, it is assumed to be the same as FILI.

If FILO is specified but does not already exist, a new PCIDSK file is created.

DBVS

Specifies the vector segment from which georeferencing information (projection, bounds) will be taken.

DBSN

Specifies a name (up to 8 characters) for the output vector layer.

DBSD

Describes (in up to 64 characters) the contents or origins of the output vector layer.

LAYERTYPE

Specifies the layer type of the output grid/graticule layer.

Supported types are:

Lines: creates a grid of lines; this is the default value
Points: creates a grid of points
Polygons: creates a grid of polygons

GRIDTYPE

Specifies the grid type for the output vector layer.

Supported values are:

Geocoded: creates a geocoded layer (easting/northing); this is the default value.
Geographic: creates a geographic layer (long/lat)

MAPUNITS

Specifies the projection definition for the output file.

If the Input vector layer (DBVS) is specified, or if georeferencing is used from the input file (FILI), this parameter is ignored.

Supported map units include:

Pixel: image pixel and line coordinates
UTM: Universal Transverse Mercator (easting and northing coordinates)
Long/Lat: longitude and latitude
Meter: image along-row and along-column, in meters
Foot: image along-row and along-column, in feet
SPCS: State Plane Coordinate System
Projection Name: the label of a user-defined projection may be specified, if the projection exists in the userproj.txt file.

MAPUNITS can specify the UTM grid zone number and row, and earth model, as follows:

UTM [mm] [r] [Ennn]

where:

[mm] is the two-digit zone number between 1 and 60.
[r] is the zone row: a single letter between N and X for north of the equator and between C and M for south of the equator. Zone rows A, B, Y, and Z are not supported; rows I and O do not exist.
[Ennn] specifies the earth model, where the model number is between 0 and 19. If the earth model is not specified, it is assumed to be E000 (Clarke 1866).

For more information about all the projections available, see "Projections and earth models" in the Technical Reference section of the CATALYST Professional help.

LLBOUNDS

Specifies whether the bound values are geographic (longitude and latitude) or geocoded (easting and northing).

If YES, the ouput bounds (values of parameters ulx, uly, lrx, and lry) are longitude and latitude values
if No, the ouput bounds are easting and northing values

Note: If MAPUNITS has the value LONG/LAT, PIXEL, METER, or FEET, this parameter is ignored.

ULX

Specifies the upper-left X coordinate of the bounds, using the coordinate system defined by LLBOUNDS.

If LLBOUNDS is YES, ULX is a longitude value, expressed as "[degrees]d[minutes]'[seconds][W|E]".

Note the absence of a double quote (") to denote seconds.
If LLBOUNDS is NO, ULX is an easting value.

ULY

Specifies the upper-left Y coordinate of the bounds, using the coordinate system defined by LLBOUNDS.

If LLBOUNDS is YES, ULY is a latitude value, expressed as "[degrees]d[minutes]'[seconds][N|S]".

Note the absence of a double quote (") to denote seconds.
If LLBOUNDS is NO, ULY is a northing value.

LRX

Specifies the lower-right X coordinate of the bounds, using the coordinate system defined by LLBOUNDS.

If LLBOUNDS is YES, LRX is a longitude value, expressed as "[degrees]d[minutes]'[seconds][W|E]".

Note the absence of a double quote (") to denote seconds.
If LLBOUNDS is NO, LRX is an easting value.

LRY

Specifies the lower-right Y coordinate of the bounds, using the coordinate system defined by LLBOUNDS.

If LLBOUNDS is YES, LRY is a latitude value, expressed as "[degrees]d[minutes]'[seconds][N|S]".

Note the absence of a double quote (") to denote seconds.
If LLBOUNDS is NO, LRY is a northing value.

XINCRE

Specifies the horizontal increment of the graticule or grid. The default value is 1.0.

YINCRE

Specifies the vertical increment of the graticule or grid. The default value is 1.0.

Details

GRATGRID creates a vector layer representing either a graticule or a grid. The vector layer can be geocoded even though it represents a graticule. The grid or graticule is created based on image extents and increments in the X and Y directions.

The GRIDTYPE (Grid Type) parameter specifies whether the new grid is geocoded (easting/northing) or geographic (lat/long). A geocoded grid has vector lines parallel to its coordinate system; when the input image has a UTM projection, for example, the output grid will follow lines of constant UTM northing or easting. A geographic grid is actually a "graticule", where the vector lines correspond to lines of constant longitude or latitude.

A geographic grid can be generated from an image with geographic or projected coordinates. A geocoded grid can only be generated from an image with projected coordinates, and not from geographic coordinates.

The X and Y increments can be specified in either Geocoded or Geographic units, depending on the Grid Type. If the Grid Type is geocoded, the increments will be geocoded units (for example, meters or feet). An increment of 1000 m creates a grid line every 1000 m. If the Grid Type is geographic, the increment units are decimal degrees. An increment of 1 (0.01 decimal degrees) creates a grid line every 36 seconds.

Examples

A geocoded line grid will be created with bounds taken from the extents of Segment 25 on irvine.pix. This segment is projected.

from pci.gratgrid import gratgrid

fili	=	"irvine.pix"
filo	=	"out_irvine.pix"
dbvs	=	[25]		# Bounds taken from vector segment 25
dbsn	=	"geocgrd1"
dbsd	=	"Geocoded bounds to Geocoded grid"
layertyp	=	"Lines"
gridtype	=	"Geocoded"
mapunits	=	''
llbounds	=	''
ulx	=	''			# No user-specified bounds
uly	=	''
lrx	=	''
lry	=	''
xincre	=	[1000]
yincre	=	[1000]		# Grid spacing is 1000x1000 m

gratgrid( fili, filo, dbvs, dbsn, dbsd, layertyp, gridtype, mapunits, llbounds, ulx, uly, lrx, lry, xincre, yincre )

A geographic point graticule will be created with user-specified geographic bounds. Because irvine_reproj.pix is in geographic (Long/Lat) coordinates, the bounds must also be geographic.

from pci.gratgrid import gratgrid

fili	=	"irvine_reproj.pix"
filo	=   ''
dbvs	=	[]			# Not using segment bounds
dbsn	=	"geoggrd2"
dbsd	=	"Geographic bounds to Geographic grid"
layertype	=	"Points"
gridtype	=	"Geographic"
mapunits	=	"LONG/LAT E000"
llbounds	=	"YES"
ulx	=	"-117.75"
uly	=	"33.75"
lrx	=	"-117.5"
lry	=	"33.5"
xincre	=	[1]
yincre	=	[1]			# Graticule spacing is 1x1 degrees

gratgrid( fili, filo, dbvs, dbsn, dbsd, layertype, gridtype, mapunits, llbounds, ulx, uly, lrx, lry, xincre, yincre )

Environments	PYTHON :: EASI :: MODELER
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GRATGRID

Create graticule or grid

Description

Parameters

Parameter descriptions

Details

Examples