ucar.nc2.dt
Interface GridCoordSystem

All Known Implementing Classes:

GridCoordSys

public interface GridCoordSystem

A Coordinate System for gridded data. Assume:

• X and Y are 1 or 2 dimensional
• T is 1 or 2 dimensional. The 2D case is that it depends on runtime.
• We can create Dates out of the T and RT coordinate values.
• Z, E, RT are 1-dimensional
• An optional VerticalTransform can provide a height or pressure coordinate that may be 1-4 dimensional.

Version:

$Revision:51 $ $Date:2006-07-12 17:13:13Z $

Author:

caron

Method Summary

int[]	findXYindexFromCoord(double x_coord, double y_coord, int[] result) Given a point in x,y coordinate space, find the x,y indices.
int[]	findXYindexFromLatLon(double lat, double lon, int[] result) Given a lat,lon point, find the x,y index of the containing grid point.
ProjectionRect	getBoundingBox() Get horizontal bounding box in projection coordinates.
java.util.List	getCoordinateAxes() Get the list of all axes.
java.util.List	getCoordinateTransforms() Get the list of all CoordinateTransforms.
DateRange	getDateRange() If there is a time coordinate, get the time covered.
java.util.List	getDomain() Get the list of dimensions used by any of the Axes in the Coordinate System.
CoordinateAxis1D	getEnsembleAxis() Get the ensemble axis.
LatLonPoint	getLatLon(int xindex, int yindex) Get the Lat/Lon coordinates of the midpoint of a grid cell, using the x,y indices.
LatLonRect	getLatLonBoundingBox() Get horizontal bounding box in lat, lon coordinates.
java.lang.String	getName() The name of the Grid Coordinate System, consisting of the list of coordinate axes, seperated by blanks.
ProjectionImpl	getProjection() Get the Projection that performs the transform math.
ProjectionCT	getProjectionCT() Get the Projection CoordinateTransform.
java.util.List	getRangesFromLatLonRect(LatLonRect llbb) Get Index Ranges for the given lat, lon bounding box.
CoordinateAxis1DTime	getRunTimeAxis() Get the RunTime axis.
CoordinateAxis	getTimeAxis() Get the Time axis, if it exists.
CoordinateAxis1DTime	getTimeAxis1D() Get the Time axis, if it exists, and its 1-dimensional.
CoordinateAxis1DTime	getTimeAxisForRun(int run_index) This is the case of a 2D time axis, which depends on the run index.
CoordinateAxis1D	getVerticalAxis() Get the Z axis.
VerticalCT	getVerticalCT() Get the Vertical CoordinateTransform, it it exists.
VerticalTransform	getVerticalTransform() Get the VerticalTransform that performs the transform math.
CoordinateAxis	getXHorizAxis() Get the X axis.
CoordinateAxis	getYHorizAxis() Get the Y axis.
boolean	hasTimeAxis() True if there is a Time Axis.
boolean	hasTimeAxis1D() True if there is a Time Axis and it is 1D.
boolean	isLatLon() Does this use lat/lon horizontal axes? If not, then the horizontal axes are GeoX, GeoY, and there must be a Projection defined.
boolean	isProductSet() True if all axes are 1 dimensional.
boolean	isRegularSpatial() True if both X and Y axes are 1 dimensional and are regularly spaced.
boolean	isZPositive() True if increasing z coordinate values means "up" in altitude

Method Detail

getName

java.lang.String getName()

The name of the Grid Coordinate System, consisting of the list of coordinate axes, seperated by blanks.

getDomain

java.util.List getDomain()

Get the list of dimensions used by any of the Axes in the Coordinate System.

Returns:

List of Dimension

getCoordinateAxes

java.util.List getCoordinateAxes()

Get the list of all axes.

Returns:

List of CoordinateAxis.

isProductSet

boolean isProductSet()

True if all axes are 1 dimensional.

getXHorizAxis

CoordinateAxis getXHorizAxis()

Get the X axis. May be 1 or 2 dimensional.

Returns:

X CoordinateAxis, may not be null.

getYHorizAxis

CoordinateAxis getYHorizAxis()

Get the Y axis. May be 1 or 2 dimensional.

Returns:

Y CoordinateAxis, may not be null.

getVerticalAxis

CoordinateAxis1D getVerticalAxis()

Get the Z axis. Must be 1 dimensional.

Returns:

Y CoordinateAxis, may be null.

getTimeAxis

CoordinateAxis getTimeAxis()

Get the Time axis, if it exists. May be 1 or 2 dimensional. If 1D, will be a CoordinateAxis1DTime. If 2D, then you can use getTimeAxisForRun(). A time coordinate must be a udunit date or ISO String, so it can always be converted to a Date. Typical meaning is the date of measurement or valid forecast time.

Returns:

the time coordinate axis, may be null.

getEnsembleAxis

CoordinateAxis1D getEnsembleAxis()

Get the ensemble axis. Must be 1 dimensional. Typical meaning is an enumeration of ensemble Model runs.

Returns:

ensemble CoordinateAxis, may be null.

getRunTimeAxis

CoordinateAxis1DTime getRunTimeAxis()

Get the RunTime axis. Must be 1 dimensional. A runtime coordinate must be a udunit date or ISO String, so it can always be converted to a Date. Typical meaning is the date that a Forecast Model Run is made.

Returns:

RunTime CoordinateAxis, may be null.

getCoordinateTransforms

java.util.List getCoordinateTransforms()

Get the list of all CoordinateTransforms.

Returns:

List of CoordinateTransform.

getProjectionCT

ProjectionCT getProjectionCT()

Get the Projection CoordinateTransform. It must exist if !isLatLon().

Returns:

ProjectionCT or null.

getProjection

ProjectionImpl getProjection()

Get the Projection that performs the transform math. Same as getProjectionCT().getProjection().

Returns:

ProjectionImpl or null.

getVerticalCT

VerticalCT getVerticalCT()

Get the Vertical CoordinateTransform, it it exists.

Returns:

VerticalCT or null.

getVerticalTransform

VerticalTransform getVerticalTransform()

Get the VerticalTransform that performs the transform math. Same as getVerticalCT().getVerticalTransform().

Returns:

VerticalTransform or null.

isLatLon

boolean isLatLon()

Does this use lat/lon horizontal axes? If not, then the horizontal axes are GeoX, GeoY, and there must be a Projection defined.

Returns:

true if lat/lon horizontal axes

getLatLonBoundingBox

LatLonRect getLatLonBoundingBox()

Get horizontal bounding box in lat, lon coordinates. For projection, only an approximation based on corners.

Returns:

LatLonRect bounding box.

getBoundingBox

ProjectionRect getBoundingBox()

Get horizontal bounding box in projection coordinates. For lat/lon, the ProjectionRect has units of degrees north and east.

Returns:

ProjectionRect bounding box.

isRegularSpatial

boolean isRegularSpatial()

True if both X and Y axes are 1 dimensional and are regularly spaced.

getRangesFromLatLonRect

java.util.List getRangesFromLatLonRect(LatLonRect llbb)
                                       throws InvalidRangeException

Get Index Ranges for the given lat, lon bounding box. For projection, only an approximation based on corners. Must have CoordinateAxis1D or 2D for x and y axis.

Parameters:

llbb - a lat/lon bounding box.

Returns:

list of 2 Range objects, first y then x.

Throws:

InvalidRangeException

findXYindexFromCoord

int[] findXYindexFromCoord(double x_coord,
                           double y_coord,
                           int[] result)

Given a point in x,y coordinate space, find the x,y indices.

Parameters:

x_coord - position in x coordinate space, ie, units of getXHorizAxis().

y_coord - position in y coordinate space, ie, units of getYHorizAxis().

result - optionally pass in the result array to use.

Returns:

int[2], 0=x, 1=y indices of the point. These will be -1 if out of range.

findXYindexFromLatLon

int[] findXYindexFromLatLon(double lat,
                            double lon,
                            int[] result)

Given a lat,lon point, find the x,y index of the containing grid point.

Parameters:

lat - latitude position.

lon - longitude position.

result - put result in here, may be null

Returns:

int[2], 0=x,1=y indices in the coordinate system of the point. These will be -1 if out of range.

getLatLon

LatLonPoint getLatLon(int xindex,
                      int yindex)

Get the Lat/Lon coordinates of the midpoint of a grid cell, using the x,y indices.

Parameters:

xindex - x index

yindex - y index

Returns:

lat/lon coordinate of the midpoint of the cell

isZPositive

boolean isZPositive()

True if increasing z coordinate values means "up" in altitude

getDateRange

DateRange getDateRange()

If there is a time coordinate, get the time covered.

Returns:

DateRange or null if no time coordinate

hasTimeAxis

boolean hasTimeAxis()

True if there is a Time Axis.

hasTimeAxis1D

boolean hasTimeAxis1D()

True if there is a Time Axis and it is 1D.

getTimeAxis1D

CoordinateAxis1DTime getTimeAxis1D()

Get the Time axis, if it exists, and its 1-dimensional.

Returns:

the time coordinate axis, may be null.

getTimeAxisForRun

CoordinateAxis1DTime getTimeAxisForRun(int run_index)

This is the case of a 2D time axis, which depends on the run index. A time coordinate must be a udunit date or ISO String, so it can always be converted to a Date.

Parameters:

run_index - which run?

Returns:

1D time axis for that run.