environmental.netcdf

Class NetcdfReader

java.lang.Object

environmental.netcdf.NetcdfReader

All Implemented Interfaces:

EnvironmentDataSource

public class NetcdfReader
extends Object
implements EnvironmentDataSource

A class to manage a NetCDF (http://my.unidata.ucar.edu/content/software/netcdf/index.html) data set, accessed to return current, temperature, density, etc., as a function of geo location and time. Typical use: NetcdfReader netds = NetcdfReader.build("/path/mydata.nc"); ... Date d = Data.valueOf("2005-05-15"); // May 15, 2005, midnight double ws[] = netds.getWaterSpeed(d, 30.115, -85.785, 50); // 3-d waterspeed vector at Gulf of Mex., 50 meters

Nested Class Summary

Nested classes/interfaces inherited from interface environmental.EnvironmentDataSource

EnvironmentDataSource.LatitudeLongitudeRectangle

Field Summary

Fields inherited from interface environmental.EnvironmentDataSource

AIR, AIR_EW, AIR_NS, AIR_PRESS, AIR_TEMP, AIR_UD, CURRENT, CURRENT_EW, CURRENT_NS, CURRENT_UD, DENS_ANOM, EW, NS, SALINITY, SEASTATE, SURF_ELEV, UD, WATER_TEMP

Method Summary

Methods

Modifier and Type	Method and Description
static NetcdfReader	build(String uri)
static NetcdfReader	build(URL url)
double	getAirSpeed_u(Date d, double lat, double lon, double depth) Return the eastward current vector component from a NetCDF dataset at the specified time and location.
double	getAirSpeed_v(Date d, double lat, double lon, double depth) Return the northward current vector component from a NetCDF dataset at the specified time and location.
double[]	getAirSpeed(Date d, double lat, double lon, double depth) Return the 2 components of the 2d air speed vector from a NetCDF dataset at the specified time and location.
EnvironmentDataSource.LatitudeLongitudeRectangle[]	getCoverage()
double	getDensAnom(Date d, double lat, double lon, double depth) Return the (interpolated) density anomaly from a NetCDF dataset at the specified time and location.
String	getDescription() Get the internally-provided description(s) of the NetcdfDatasets.
double	getNamedValue(String name, Date d, double lat, double lon, double depth) Return the value of the named variable from a NetCDF dataset at the specified time and location.
int	getParameterMask() Get the mask of parameter bits which are requested-of and supported-by this data set
double	getSalinity(Date d, double lat, double lon, double depth) Return the (interpolated) water salinity from a NetCDF dataset at the specified time and location.
double	getSurfEl(Date d, double lat, double lon, double depth) Return the (interpolated) surface elevation from a NetCDF dataset at the specified time and location.
Date	getTimeBase(double lat, double lon) Get the absolute time base of the Netcdf dataset which covers the specified location.
double	getVariable(int var, double lat, double lon, double depth, Date date)
double	getVariable(int var, double lat, double lon, double depth, long time)
double[]	getVariableAr(int var, double lat, double lon, double depth, Date date)
double[]	getVariableAr(int var, double lat, double lon, double depth, long time)
List<String>	getVariableList(double lat, double lon) Return a list of the variables in the Netcdf datasat which covers the specified location.
double	getWaterSpeed_u(Date d, double lat, double lon, double depth) Return the eastward current vector component from a NetCDF dataset at the specified time and location.
double	getWaterSpeed_v(Date d, double lat, double lon, double depth) Return the northward current vector component from a NetCDF dataset at the specified time and location.
double	getWaterSpeed_w(Date d, double lat, double lon, double depth) Return the downward current vector component from a NetCDF dataset at the specified time and location.
double[]	getWaterSpeed(Date d, double lat, double lon, double depth) Return the 3 components of the 3d current vector from a NetCDF dataset at the specified time and location.
double	getWaterTemp(Date d, double lat, double lon, double depth) Return the (interpolated) water temperature from a NetCDF dataset at the specified time and location.
void	setDescription(String s)
void	setParamMask(int mask) Set the mask of parameter bits which this data set has been instructed to provide and can provide.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

build

public static NetcdfReader build(String uri)
                          throws IOException

Throws:

IOException

build

public static NetcdfReader build(URL url)
                          throws IOException

Throws:

IOException

getCoverage

public EnvironmentDataSource.LatitudeLongitudeRectangle[] getCoverage()

Specified by:

getCoverage in interface EnvironmentDataSource

getParameterMask

public int getParameterMask()

Get the mask of parameter bits which are requested-of and supported-by this data set

Specified by:

getParameterMask in interface EnvironmentDataSource

Returns:

parameter mask

setParamMask

public void setParamMask(int mask)

Set the mask of parameter bits which this data set has been instructed to provide and can provide.

Specified by:

setParamMask in interface EnvironmentDataSource

Parameters:

mask -

getVariable

public double getVariable(int var,
                 double lat,
                 double lon,
                 double depth,
                 Date date)
                   throws EnviroException

Specified by:

getVariable in interface EnvironmentDataSource

Throws:

EnviroException

getVariableAr

public double[] getVariableAr(int var,
                     double lat,
                     double lon,
                     double depth,
                     Date date)
                       throws EnviroException

Specified by:

getVariableAr in interface EnvironmentDataSource

Throws:

EnviroException

getVariable

public double getVariable(int var,
                 double lat,
                 double lon,
                 double depth,
                 long time)
                   throws EnviroException

Specified by:

getVariable in interface EnvironmentDataSource

Throws:

EnviroException

getVariableAr

public double[] getVariableAr(int var,
                     double lat,
                     double lon,
                     double depth,
                     long time)
                       throws EnviroException

Specified by:

getVariableAr in interface EnvironmentDataSource

Throws:

EnviroException

getDensAnom

public double getDensAnom(Date d,
                 double lat,
                 double lon,
                 double depth)
                   throws Exception

Return the (interpolated) density anomaly from a NetCDF dataset at the specified time and location. Units = kg/m3.

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

density anomaly at location and time in kg/m3

Throws:

Exception - if parameters are outside of dataset range

getSurfEl

public double getSurfEl(Date d,
               double lat,
               double lon,
               double depth)
                 throws Exception

Return the (interpolated) surface elevation from a NetCDF dataset at the specified time and location.

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - (redundant) vertical location coordinate, downwards direction is positive, units = meters

Returns:

surface elevation at location and time

Throws:

Exception - if parameters are outside of dataset range

getSalinity

public double getSalinity(Date d,
                 double lat,
                 double lon,
                 double depth)
                   throws Exception

Return the (interpolated) water salinity from a NetCDF dataset at the specified time and location. Units = psu;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

salinity at location and time in psu

Throws:

Exception - if parameters are outside of dataset range

getWaterTemp

public double getWaterTemp(Date d,
                  double lat,
                  double lon,
                  double depth)
                    throws Exception

Return the (interpolated) water temperature from a NetCDF dataset at the specified time and location. Units = degC;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

temperature at location and time in degC

Throws:

Exception - if parameters are outside of dataset range

getWaterSpeed

public double[] getWaterSpeed(Date d,
                     double lat,
                     double lon,
                     double depth)
                       throws Exception

Return the 3 components of the 3d current vector from a NetCDF dataset at the specified time and location. Units = m/s;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

eastward, northward, downward velocity components in m/s

Throws:

Exception - if parameters are outside of dataset range

getWaterSpeed_u

public double getWaterSpeed_u(Date d,
                     double lat,
                     double lon,
                     double depth)
                       throws Exception

Return the eastward current vector component from a NetCDF dataset at the specified time and location. Units = m/s;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

eastward current at location and time in m/s

Throws:

Exception - if parameters are outside of dataset range

getWaterSpeed_v

public double getWaterSpeed_v(Date d,
                     double lat,
                     double lon,
                     double depth)
                       throws Exception

Return the northward current vector component from a NetCDF dataset at the specified time and location. Units = m/s;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

eastward current at location and time in m/s

Throws:

Exception - if parameters are outside of dataset range

getWaterSpeed_w

public double getWaterSpeed_w(Date d,
                     double lat,
                     double lon,
                     double depth)
                       throws Exception

Return the downward current vector component from a NetCDF dataset at the specified time and location. Units = m/s, downward positive;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

downward current at location and time in m/s

Throws:

Exception - if parameters are outside of dataset range

getAirSpeed

public double[] getAirSpeed(Date d,
                   double lat,
                   double lon,
                   double depth)
                     throws Exception

Return the 2 components of the 2d air speed vector from a NetCDF dataset at the specified time and location. Units = m/s;

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - (not used) vertical location coordinate, downwards direction is positive, units = meters

Returns:

eastward, northward, air velocity components in m/s

Throws:

Exception - if parameters are outside of dataset range

getAirSpeed_u

public double getAirSpeed_u(Date d,
                   double lat,
                   double lon,
                   double depth)
                     throws Exception

Return the eastward current vector component from a NetCDF dataset at the specified time and location. Units = m/s.

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - (not used) vertical location coordinate, downwards direction is positive, units = meters

Returns:

eastward air velocity at location and time in m/s

Throws:

Exception - if parameters are outside of dataset range

getAirSpeed_v

public double getAirSpeed_v(Date d,
                   double lat,
                   double lon,
                   double depth)
                     throws Exception

Return the northward current vector component from a NetCDF dataset at the specified time and location. Units = m/s.

Parameters:

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - (not used) vertical location coordinate, downwards direction is positive, units = meters

Returns:

northward air velocity at location and time in m/s

Throws:

Exception - if parameters are outside of dataset range

getNamedValue

public double getNamedValue(String name,
                   Date d,
                   double lat,
                   double lon,
                   double depth)
                     throws Exception

Return the value of the named variable from a NetCDF dataset at the specified time and location. Units = m/s.

Parameters:

name - variable name in dataset

d - time coordinate

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

depth - vertical location coordinate, downwards direction is positive, units = meters

Returns:

variable value at location and time in m/s

Throws:

Exception - if parameters are outside of dataset range

getVariableList

public List<String> getVariableList(double lat,
                           double lon)
                             throws Exception

Return a list of the variables in the Netcdf datasat which covers the specified location.

Parameters:

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

Returns:

list of Strings: variable name plus tab character plus variable description

Throws:

Exception

getDescription

public String getDescription()

Get the internally-provided description(s) of the NetcdfDatasets.

Specified by:

getDescription in interface EnvironmentDataSource

Returns:

String description.

setDescription

public void setDescription(String s)

Specified by:

setDescription in interface EnvironmentDataSource

getTimeBase

public Date getTimeBase(double lat,
               double lon)
                 throws IOException

Get the absolute time base of the Netcdf dataset which covers the specified location.

Parameters:

lat - latitude coordinate (decimal degrees)

lon - longitude coordinate (decimal degrees)

Returns:

time origin of the dataset. Time coordinate units in the dataset are relative to this absolute time.

Throws:

IOException