ucar.nc2.dt.grid
Class GridCoordSys

java.lang.Object
  ucar.nc2.dataset.CoordinateSystem
      ucar.nc2.dt.grid.GridCoordSys

All Implemented Interfaces:

GridCoordSystem

public class GridCoordSys
extends CoordinateSystem
implements GridCoordSystem

A georeferencing "gridded" CoordinateSystem. This describes a "grid" of coordinates, which implies a connected topology such that values next to each other in index space are next to each other in coordinate space. Note: these classes should be considered experimental and will likely be refactored in the next release.

This currently assumes that the CoordinateSystem

1. is georeferencing (has Lat, Lon or GeoX, GeoY axes)
2. x, y are 1 or 2-dimensional axes.
3. z, t are 1-dimensional axes.

This is the common case for georeferencing coordinate systems. Mathematically it is a product set: {X,Y} x {Z} x {T}. The x and y axes may be 1 or 2 dimensional.

A CoordinateSystem may have multiple horizontal and vertical axes. GridCoordSys chooses one axis corresponding to X, Y, Z, and T. It gives preference to one dimensional axes (CoordinateAxis1D).

Version:

$Revision: 70 $ $Date: 2006-07-13 15:16:05Z $

Author:

caron

Constructor Summary

GridCoordSys(CoordinateSystem cs, java.lang.StringBuffer sbuff)
Create a GridCoordSys from an existing Coordinate System.

GridCoordSys(GridCoordSys from, Range t_range, Range z_range, Range y_range, Range x_range)
Create a GridCoordSys as a section of an existing GridCoordSys.

Method Summary

int	findTimeIndexFromDate(java.util.Date d) Given a Date, find the corresponding time index on the time coordinate axis.
int[]	findXYCoordElement(double x_coord, double y_coord, int[] result) Deprecated. use findXYindexFromCoord
int[]	findXYindexFromCoord(double x_coord, double y_coord, int[] result) Given a point in x,y coordinate space, find the x,y index in the coordinate system.
ProjectionRect	getBoundingBox() Get the x,y bounding box in projection coordinates.
DateRange	getDateRange() If there is a time coordinate, get the time covered.
DateUnit	getDateUnit()
CoordinateAxis1D	getEnsembleAxis() get the Ensemble axis, else null
LatLonRect	getLatLonBoundingBox() Get horizontal bounding box in lat, lon coordinates.
java.util.List	getLatLonBoundingBox(LatLonRect rect) Deprecated. use getRangesFromLatRect.
int	getLevelIndex(java.lang.String name) Get the index corresponding to the level name.
java.lang.String	getLevelName(int index) Get the String name for the ith level(z) coordinate.
java.util.List	getLevels() Get the list of level names, to be used for user selection.
ProjectionImpl	getProjection() get the projection
java.util.List	getRangesFromLatLonRect(LatLonRect rect) Get Index Ranges for the given lat, lon bounding box.
CoordinateAxis1DTime	getRunTimeAxis() get the RunTime axis, else null
CoordinateAxis	getTimeAxis() get the Time axis
CoordinateAxis1DTime	getTimeAxis1D() get the Time axis, if its 1-dimensional
CoordinateAxis1DTime	getTimeAxisForRun(int run_index) This is the case of a 2D time axis, which depends on the run index.
java.util.Date[]	getTimeDates() Get the list of times as Dates.
int	getTimeIndex(java.lang.String name) Get the index corresponding to the time name.
java.lang.String	getTimeName(int index) Get the string name for the ith time coordinate.
TimeUnit	getTimeResolution() return null if !isRegular()
java.util.List	getTimes() Get the list of time names, to be used for user selection.
CoordinateAxis1D	getVerticalAxis() get the Vertical axis (either Geoz, Height, or Pressure)
VerticalCT	getVerticalCT() Get the Vertical CoordinateTransform, it it exists.
VerticalTransform	getVerticalTransform() Get the vertical transform, if any.
CoordinateAxis	getXHorizAxis() get the X Horizontal axis (either GeoX or Lon)
CoordinateAxis	getYHorizAxis() get the Y Horizontal axis (either GeoY or Lat)
boolean	hasTimeAxis() True if there is a Time Axis.
boolean	hasTimeAxis1D() True if there is a Time Axis and it is 1D.
boolean	isDate() is there a time coordinate, and can it be expressed as a Date?
static boolean	isGridCoordSys(java.lang.StringBuffer sbuff, CoordinateSystem cs) Determine if this CoordinateSystem can be made into a GridCoordSys.
boolean	isLatLon() is this a Lat/Lon coordinate system?
boolean	isRegularSpatial() true if x and y axes are CoordinateAxis1D and are regular
boolean	isZPositive() true if increasing z coordinate values means "up" in altitude
static GridCoordSys	makeGridCoordSys(java.lang.StringBuffer sbuff, CoordinateSystem cs, VariableEnhanced v) Determine if the CoordinateSystem cs can be made into a GridCoordSys for the Variable v.
java.lang.String	toString() String representation.

Methods inherited from class ucar.nc2.dataset.CoordinateSystem

addCoordinateTransform, addCoordinateTransforms, containsAxes, containsAxis, containsAxisType, containsAxisTypes, containsDomain, equals, findAxis, getAzimuthAxis, getCoordinateAxes, getCoordinateTransforms, getDomain, getElevationAxis, getHeightAxis, getLatAxis, getLonAxis, getName, getPressureAxis, getProjectionCT, getRadialAxis, getRankDomain, getRankRange, getTaxis, getXaxis, getYaxis, getZaxis, hashCode, hasVerticalAxis, isComplete, isGeoReferencing, isGeoXY, isImplicit, isProductSet, isRadial, isRegular, makeName

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface ucar.nc2.dt.GridCoordSystem

getCoordinateAxes, getCoordinateTransforms, getDomain, getName, getProjectionCT, isProductSet

Constructor Detail

GridCoordSys

public GridCoordSys(CoordinateSystem cs,
                    java.lang.StringBuffer sbuff)

Create a GridCoordSys from an existing Coordinate System. This will choose which axes are the XHoriz, YHoriz, Vertical, and Time. If theres a Projection, it will set its map area

GridCoordSys

public GridCoordSys(GridCoordSys from,
                    Range t_range,
                    Range z_range,
                    Range y_range,
                    Range x_range)
             throws InvalidRangeException

Create a GridCoordSys as a section of an existing GridCoordSys. This will create sections of the corresponding CoordinateAxes.

Parameters:

from - copy this GridCoordSys

t_range - subset the time dimension, or null if you want all of it

z_range - subset the vertical dimension, or null if you want all of it

y_range - subset the y dimension, or null if you want all of it

x_range - subset the x dimension, or null if you want all of it

Throws:

InvalidRangeException

Method Detail

isGridCoordSys

public static boolean isGridCoordSys(java.lang.StringBuffer sbuff,
                                     CoordinateSystem cs)

Determine if this CoordinateSystem can be made into a GridCoordSys. This currently assumes that the CoordinateSystem:

1. is georeferencing (cs.isGeoReferencing())
2. x, y are 1 or 2-dimensional axes.
3. z, t, if they exist, are 1-dimensional axes.
4. domain rank > 1

Parameters:

cs - the CoordinateSystem to test

Returns:

true if it can be made into a GridCoordSys.

See Also:

CoordinateSystem.isGeoReferencing()

makeGridCoordSys

public static GridCoordSys makeGridCoordSys(java.lang.StringBuffer sbuff,
                                            CoordinateSystem cs,
                                            VariableEnhanced v)

Determine if the CoordinateSystem cs can be made into a GridCoordSys for the Variable v.

Parameters:

sbuff - put debug information into this StringBuffer; may be null.

cs - CoordinateSystem to check.

v - Variable to check.

Returns:

the GridCoordSys made from cs, else null.

getVerticalTransform

public VerticalTransform getVerticalTransform()

Get the vertical transform, if any.

Specified by:

getVerticalTransform in interface GridCoordSystem

Returns:

VerticalTransform or null.

getVerticalCT

public VerticalCT getVerticalCT()

Description copied from interface: GridCoordSystem

Get the Vertical CoordinateTransform, it it exists.

Specified by:

getVerticalCT in interface GridCoordSystem

Returns:

VerticalCT or null.

getXHorizAxis

public CoordinateAxis getXHorizAxis()

get the X Horizontal axis (either GeoX or Lon)

Specified by:

getXHorizAxis in interface GridCoordSystem

Returns:

X CoordinateAxis, may not be null.

getYHorizAxis

public CoordinateAxis getYHorizAxis()

get the Y Horizontal axis (either GeoY or Lat)

Specified by:

getYHorizAxis in interface GridCoordSystem

Returns:

Y CoordinateAxis, may not be null.

getVerticalAxis

public CoordinateAxis1D getVerticalAxis()

get the Vertical axis (either Geoz, Height, or Pressure)

Specified by:

getVerticalAxis in interface GridCoordSystem

Returns:

Y CoordinateAxis, may be null.

getTimeAxis

public CoordinateAxis getTimeAxis()

get the Time axis

Specified by:

getTimeAxis in interface GridCoordSystem

Returns:

the time coordinate axis, may be null.

getTimeAxis1D

public CoordinateAxis1DTime getTimeAxis1D()

get the Time axis, if its 1-dimensional

Specified by:

getTimeAxis1D in interface GridCoordSystem

Returns:

the time coordinate axis, may be null.

getRunTimeAxis

public CoordinateAxis1DTime getRunTimeAxis()

get the RunTime axis, else null

Specified by:

getRunTimeAxis in interface GridCoordSystem

Returns:

RunTime CoordinateAxis, may be null.

getEnsembleAxis

public CoordinateAxis1D getEnsembleAxis()

get the Ensemble axis, else null

Specified by:

getEnsembleAxis in interface GridCoordSystem

Returns:

ensemble CoordinateAxis, may be null.

getProjection

public ProjectionImpl getProjection()

get the projection

Specified by:

getProjection in interface GridCoordSystem

Overrides:

getProjection in class CoordinateSystem

Returns:

ProjectionImpl or null if none.

getLevels

public java.util.List getLevels()

Get the list of level names, to be used for user selection. The ith one refers to the ith level coordinate.

Returns:

List of ucar.nc2.util.NamedObject, or empty list.

getTimes

public java.util.List getTimes()

Get the list of time names, to be used for user selection. The ith one refers to the ith time coordinate.

Returns:

List of ucar.nc2.util.NamedObject, or empty list.

getTimeDates

public java.util.Date[] getTimeDates()

Get the list of times as Dates. Only valid if isDate() is true;

Returns:

array of java.util.Date, or null.

isLatLon

public boolean isLatLon()

is this a Lat/Lon coordinate system?

Specified by:

isLatLon in interface GridCoordSystem

Overrides:

isLatLon in class CoordinateSystem

Returns:

true if lat/lon horizontal axes

isDate

public boolean isDate()

is there a time coordinate, and can it be expressed as a Date?

isZPositive

public boolean isZPositive()

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

Specified by:

isZPositive in interface GridCoordSystem

isRegularSpatial

public boolean isRegularSpatial()

true if x and y axes are CoordinateAxis1D and are regular

Specified by:

isRegularSpatial in interface GridCoordSystem

findXYindexFromCoord

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

Given a point in x,y coordinate space, find the x,y index in the coordinate system. Not implemented yet for 2D.

Specified by:

findXYindexFromCoord in interface GridCoordSystem

Parameters:

x_coord - position in x coordinate space.

y_coord - position in y coordinate space.

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.

findXYCoordElement

public int[] findXYCoordElement(double x_coord,
                                double y_coord,
                                int[] result)

Deprecated. use findXYindexFromCoord

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

findTimeIndexFromDate

public int findTimeIndexFromDate(java.util.Date d)

Given a Date, find the corresponding time index on the time coordinate axis. Can only call this is hasDate() is true. This will return

• i, if time(i) <= d < time(i+1).
• -1, if d < time(0)
• n-1, if d > time(n-1), where n is length of time coordinates

Parameters:

d - date to look for

Returns:

corresponding time index on the time coordinate axis

Throws:

java.lang.UnsupportedOperationException - is no time axis or isDate() false

getLevelName

public java.lang.String getLevelName(int index)

Get the String name for the ith level(z) coordinate.

Parameters:

index - which level coordinate

Returns:

level name

getLevelIndex

public int getLevelIndex(java.lang.String name)

Get the index corresponding to the level name.

Parameters:

name - level name

Returns:

level index, or -1 if not found

getTimeName

public java.lang.String getTimeName(int index)

Get the string name for the ith time coordinate.

Parameters:

index - which time coordinate

Returns:

time name.

getTimeIndex

public int getTimeIndex(java.lang.String name)

Get the index corresponding to the time name.

Parameters:

name - time name

Returns:

time index, or -1 if not found

getDateRange

public DateRange getDateRange()

Description copied from interface: GridCoordSystem

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

Specified by:

getDateRange in interface GridCoordSystem

Returns:

DateRange or null if no time coordinate

hasTimeAxis

public boolean hasTimeAxis()

True if there is a Time Axis.

Specified by:

hasTimeAxis in interface GridCoordSystem

Overrides:

hasTimeAxis in class CoordinateSystem

hasTimeAxis1D

public boolean hasTimeAxis1D()

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

Specified by:

hasTimeAxis1D in interface GridCoordSystem

getTimeAxisForRun

public CoordinateAxis1DTime getTimeAxisForRun(int run_index)

Description copied from interface: GridCoordSystem

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.

Specified by:

getTimeAxisForRun in interface GridCoordSystem

Parameters:

run_index - which run?

Returns:

1D time axis for that run.

getDateUnit

public DateUnit getDateUnit()
                     throws java.lang.Exception

Throws:

java.lang.Exception

getTimeResolution

public TimeUnit getTimeResolution()
                           throws java.lang.Exception

return null if !isRegular()

Throws:

java.lang.Exception

getBoundingBox

public ProjectionRect getBoundingBox()

Get the x,y bounding box in projection coordinates.

Specified by:

getBoundingBox in interface GridCoordSystem

Returns:

ProjectionRect bounding box.

getLatLonBoundingBox

public LatLonRect getLatLonBoundingBox()

Get horizontal bounding box in lat, lon coordinates.

Specified by:

getLatLonBoundingBox in interface GridCoordSystem

Returns:

lat, lon bounding box.

getLatLonBoundingBox

public java.util.List getLatLonBoundingBox(LatLonRect rect)

Deprecated. use getRangesFromLatRect.

Get Index Ranges for the given lat, lon bounding box.

getRangesFromLatLonRect

public java.util.List getRangesFromLatLonRect(LatLonRect rect)

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

Specified by:

getRangesFromLatLonRect in interface GridCoordSystem

Parameters:

rect - a lat/lon bounding box.

Returns:

list of 2 Range objects, first y then x.

toString

public java.lang.String toString()

String representation.

Overrides:

toString in class CoordinateSystem