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|
;+
; NAME:
; NCDF_VARIABLE
;
; PURPOSE:
;
; The pupose of this NCDF_Variable object is to store information about
; a netCDF variable. The object is principally used as a utility routine
; for the NCDF_FILE object. Given the variable name, the object will acquire
; additional information about the variable from the netCDF file containing
; the variable.
;
; AUTHOR:
;
; FANNING SOFTWARE CONSULTING
; David Fanning, Ph.D.
; 1645 Sheely Drive
; Fort Collins, CO 80526 USA
; Phone: 970-221-0438
; E-mail: david@idlcoyote.com
; Coyote's Guide to IDL Programming: http://www.idlcoyote.com
;
; CATEGORY:
;
; File I/O
;
; CALLING SEQUENCE:
;
; IDL> varObj = Obj_New('NCDF_VARIABLE', varName, parent)
;
; ARGUMENTS:
;
; varName: The case sensitive name of a netCDF variable that is stored in the
; netCDF file. (Input and required.)
;
; parent: The object reference (NCDF_FILE object) of the netCDF file. In other words, the
; object reference of the file that contains this attribute. (Input and required.)
;
; KEYWORD PARAMETERS:
;
; None.
;
; METHODS:
;
; The following methods are available. Each is documented in front of the method.
;
; varObject -> AddAttr
; varAttrNames = varObject -> GetAttrNames()
; dimIDs = varObject -> GetDimIDs()
; dimNames = varObject -> GetDimNames()
; varAttrValue = varObject -> GetAttrValue()
; varID = varObject -> GetID()
; varName = varObject -> GetName()
; propertyValue = varObject -> GetProperty(attrProperty)
; varValue = varObject -> GetValue()
; varObject -> ParseVariable
;
;
; MODIFICATION HISTORY:
; Written by: David W. Fanning, 3 Feb 2010.
; Changes to the way dimensions of length 0 are handled. 11 Feb 2010. DWF.
; Added GetInfo method. 20 Mar 2010. DWF.
; Added MISSINGINDICES and FILLVALUE keywords to GetValue method to return the indices
; and the value of missing data. 20 Mar 2010. DWF.
; Modified the GetValue method so that if the data returned is scaled and/or offset
; then the "missing" data value is preserved, although its data type may change.
; In other words, the "missing" data is not scaled or offset. 20 Mar 2010. DWF.
; Added output keywords SCALE_FACTOR, ADD_OFFSET, and DATATYPE to the GetValue method
; so that these values can be returned to the caller at run-time. 29 April 2010. DWF.
; Modified AddAttr method to allow for additional data types in attributes, specifically
; INT data type. 3 June 2013. DWF.
; Had to modify AddAttr method again to allow compatibility with IDL
; versions below 8.1. 26 July 2013. DWF.
; Set Default attribute searching to case insensitive via
; idl-coyote/coyote#13 21 Oct 2017. MHS (mandrakos)
;
;-
;******************************************************************************************;
; Copyright (c) 2010, by Fanning Software Consulting, Inc. ;
; All rights reserved. ;
; ;
; Redistribution and use in source and binary forms, with or without ;
; modification, are permitted provided that the following conditions are met: ;
; ;
; * Redistributions of source code must retain the above copyright ;
; notice, this list of conditions and the following disclaimer. ;
; * Redistributions in binary form must reproduce the above copyright ;
; notice, this list of conditions and the following disclaimer in the ;
; documentation and/or other materials provided with the distribution. ;
; * Neither the name of Fanning Software Consulting, Inc. nor the names of its ;
; contributors may be used to endorse or promote products derived from this ;
; software without specific prior written permission. ;
; ;
; THIS SOFTWARE IS PROVIDED BY FANNING SOFTWARE CONSULTING, INC. ''AS IS'' AND ANY ;
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES ;
; OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT ;
; SHALL FANNING SOFTWARE CONSULTING, INC. BE LIABLE FOR ANY DIRECT, INDIRECT, ;
; INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED ;
; TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; ;
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ;
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ;
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS ;
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ;
;******************************************************************************************;
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::AddAttr
;
; Purpose:
;
; Adds a variable attribute to the object.
;
; Method Syntax:
;
; varObject -> AddAttr, attrName, attrValue, DATATYPE=datatype
;
; Auguments:
;
; attrName: A case sensitive name of a variable attribute.
; attrValue: The value of the variable attribute.
;
; Keywords:
;
; DATATYPE: An input keyword that contains the netCDF data type of
; the variable attribute. If not provided the data type is
; determined from the attribute value.
;
;------------------------------------------------------------------------------------------;
PRO NCDF_Variable::AddAttr, attrName, attrValue, DATATYPE=datatype
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorlogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN
ENDIF
; Check parameters.
IF N_Elements(attrName) EQ 0 THEN Message, 'The attribute name is required.'
IF N_Elements(attrValue) EQ 0 THEN Message, 'The attribute value is required.'
; Set the appropriate netCDF data type keyword.
IF N_Elements(datatype) EQ 0 THEN datatype = NCDF_CastDataType(attrValue)
CASE StrUpCase(datatype) OF
'BYTE': tbyte = 1
'CHAR': tchar = 1
'INT': tshort = 1
'DOUBLE': tdouble = 1
'FLOAT': tfloat = 1
'LONG': tlong = 1
'SHORT': tshort = 1
'STRING': tstring = 1
'UBYTE': tubyte = 1
'UINT64': tuint64 = 1
'ULONG': tulong = 1
'UINT': tushort = 1
ELSE: Message, 'Unknown DATATYPE for netCDF files: ' + datatype
ENDCASE
; The file has to be writable to add an attribute.
IF ~self.parent -> GetProperty('WRITABLE') THEN $
Message, 'Cannot add a attribute to a READ-ONLY file.'
; Put the file into define mode
self.parent -> SetMode, /DEFINE
; Check to see if this attribute in _FillValue. If it is,
; make sure the data type of the attribute matches the
; data type of the variable, or there can be lots of trouble
; later on.
IF (attrName EQ '_FillValue') THEN BEGIN
IF self.datatype NE datatype THEN BEGIN
Message, "The _FillValue attribute's datatype (" + $
datatype + ") does not match the datatype (" + $
self.datatype + ") of the variable."
ENDIF
ENDIF
; Add the attribute to the file. Some attributes added only after IDL 7.2.
fileID = self.parent -> GetFileID()
IF (Float(!Version.Release) GE 8.1) THEN BEGIN
NCDF_AttPut, fileID, self.ID, attrName, attrValue, $
BYTE=tbyte, $
CHAR=tchar, $
DOUBLE=tdouble, $
FLOAT=tfloat, $
LENGTH=length, $
LONG=tlong, $
SHORT=tshort, $
STRING=tstring, $
UBYTE=tubyte, $
UINT64=tuint64, $
ULONG=tulong, $
USHORT=tushort
ENDIF ELSE BEGIN
NCDF_AttPut, fileID, self.ID, attrName, attrValue, $
BYTE=tbyte, $
CHAR=tchar, $
DOUBLE=tdouble, $
FLOAT=tfloat, $
LENGTH=length, $
LONG=tlong, $
SHORT=tshort
ENDELSE
; Add the attribute to this object's attribute list. Use "self" rather
; then the variable name to avoid excess trips through ParseFile from the
; HASVAR method.
attrObj = Obj_New('NCDF_Attribute', attrName, self.parent, VARNAME=self)
self.attrs -> Add, attrObj
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetAttrNames
;
; Purpose:
;
; Returns a string array with the names of all the variable's attributes.
;
; Method Syntax:
;
; attrNames = GetAttrNames(COUNT=attrCount)
;
; Auguments:
;
; None.
;
; Keywords:
;
; COUNT: An output keyword containing the number of attribute names found.
;
;
; Return Value:
;
; attrNames: A string array with the names of all the variable's attributes.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetAttrNames, COUNT=attrCount
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
; Count the number of attribute objects.
attrCount = self.attrs -> Count()
; If there are no attributes, return null string.
IF attrCount EQ 0 THEN RETURN, ""
attrNames = StrArr(attrCount)
FOR j=0,attrCount-1 DO BEGIN
thisObj = self.attrs -> Get(POSITION=j)
attrNames[j] = thisObj -> GetName()
ENDFOR
; Return a scalar if necessary.
IF N_Elements(attrNames) EQ 1 THEN attrNames = attrNames[0]
RETURN, attrNames
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetAttrValue
;
; Purpose:
;
; Returns the value of a variable attribute.
;
; Method Syntax:
;
; attrValue = GetAttrValue(attrName, DATATYPE=datatype)
;
; Arguments:
;
; attrName: A case name of a variable attribute. Case sensitivity
; determined by self.caseSensitiveAttributes
;
; Keywords:
;
; DATATYPE: An ouput keyword that contains the netCDF data type of
; the variable attribute.
;
; Return Value:
;
; attrValue: The value of the variable's attribute.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetAttrValue, attrName, DATATYPE=datatype
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
IF N_Elements(attrName) EQ 0 THEN Message, 'An attribute name or object reference is required.'
; Were you passed the name of a attribute or an attribute object?
CASE Size(attrName, /TNAME) OF
'STRING': BEGIN
attrObj = self.attrs -> FindByName(attrName, COUNT=attrcount, CASE_SENSITIVE = self.caseSensitiveAttributes)
IF attrcount EQ 0 THEN Message, 'Cannot find an attribute object with name ' + attrName + '.'
IF ~Obj_Valid(attrObj) THEN Message, 'Invalid object with name "' + attrName + '" has been found.'
END
'OBJREF': BEGIN
attrObj = attrName
END
ELSE: Message, 'Input attribute name or object is the wrong data type.'
ENDCASE
; Get the data.
attrData = attrObj -> GetValue()
datatype = attrObj -> GetProperty('DATATYPE')
RETURN, attrData
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetDimIDs
;
; Purpose:
;
; Returns the dimension IDs of the dimensions associated with this image.
;
; Method Syntax:
;
; dimIDs = GetDimIDs(COUNT=dimCount)
;
; Auguments:
;
; None.
;
; Keywords:
;
; COUNT: An ouput keyword that contains number of dimension IDs returned. ;
;
; Return Value:
;
; dimIDs: A long arry of dimension identifiers.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetDimIDs, COUNT=dimCount
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
; Get the dimension IDs.
IF Ptr_Valid(self.dims) THEN BEGIN
dimIDs = *self.dims
dimCount = self.ndims
ENDIF ELSE BEGIN
dimIDs = -1
dimCount = 0
ENDELSE
RETURN, dimIDs
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetDimNames
;
; Purpose:
;
; Returns the dimension names of the dimensions associated with this image.
;
; Method Syntax:
;
; dimNames = GetDimNames(COUNT=dimCount)
;
; Auguments:
;
; None.
;
; Keywords:
;
; COUNT: An ouput keyword that contains number of dimension names returned.
;
; Return Value:
;
; dimNames: A string array containing the dimension names.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetDimNames, COUNT=dimCount
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
; Get the dimension names.
IF Ptr_Valid(self.dimNames) THEN BEGIN
dimNames = *self.dimNames
dimCount = self.ndims
ENDIF ELSE BEGIN
dimNames = ""
dimCount = 0
ENDELSE
RETURN, dimNames
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetDimSizes
;
; Purpose:
;
; Returns the dimension sizes of the dimensions associated with this image.
;
; Method Syntax:
;
; dimSizes = GetDimSizes(COUNT=dimCount)
;
; Auguments:
;
; None.
;
; Keywords:
;
; COUNT: An ouput keyword that contains number of dimension sizes returned.
;
; Return Value:
;
; dimSizes: A long array of dimension sizes.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetDimSizes, COUNT=dimCount
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
; Get the dimension sizes.
IF Ptr_Valid(self.dimensions) THEN BEGIN
dimSizes = *self.dimensions
dimCount = N_Elements(dimSizes)
ENDIF ELSE BEGIN
dimSizes = 0
dimCount = 0
ENDELSE
RETURN, dimSizes
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetID
;
; Purpose:
;
; Returns the netCDF variable ID.
;
; Method Syntax:
;
; varID = GetID()
;
; Auguments:
;
; None.
;
; Keywords:
;
; None.
;
; Return Value:
;
; varID: A long integer containing the netCDF variable ID.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetID
RETURN, self.ID
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetInfo
;
; Purpose:
;
; Returns information about the variable from the file.
;
; Method Syntax:
;
; info = obj -> GetInfo()
;
; Auguments:
;
; None.
;
; Keywords:
;
; None.
;
; Return Value:
;
; info: A structure contains the following fields.
;
; info = { dims: varObj -> GetDimSizes(), $
; dimNames: varObj -> GetDimNames(), $
; attrNames: varObj -> GetAttrNames(), $
; dataType: varObj -> GetProperty('datatype'), $
; nattrs: varObj -> GetProperty('nattrs'), $
; ndims: varObj -> GetProperty('ndims') }
;
; In addition, the structure will contain the fields "scale_factor," "add_offset,"
; and "_FillValue" if these attributes are available for the variable.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetInfo
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
; Collect and return information about the variable.
info = { dims: self -> GetDimSizes(), $
dimNames: self -> GetDimNames(), $
attrNames: self -> GetAttrNames(), $
dataType: self -> GetProperty('datatype'), $
nattrs: self -> GetProperty('nattrs'), $
ndims: self -> GetProperty('ndims') }
; Add additional information to the info structure, if it is available.
; This will include scale_factor, add_offset, and _FillValue attribute values.
attrNames = self -> GetAttrNames()
attrIndex = Where(attrNames EQ 'scale_factor', count)
IF count GT 0 THEN info = Create_Struct(info, 'scale_factor', $
self -> GetAttrValue('scale_factor'))
attrIndex = Where(attrNames EQ 'add_offset', count)
IF count GT 0 THEN info = Create_Struct(info, 'add_offset', $
self -> GetAttrValue('add_offset'))
attrIndex = Where(attrNames EQ 'missing_value', count)
IF count GT 0 THEN info = Create_Struct(info, '_FillValue', $
self -> GetAttrValue('missing_value'))
attrIndex = Where(attrNames EQ '_FillValue', count)
IF count GT 0 THEN info = Create_Struct(info, '_FillValue', $
self -> GetAttrValue('_FillValue'))
RETURN, info
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetName
;
; Purpose:
;
; Returns the variable name.
;
; Method Syntax:
;
; varName = GetName()
;
; Auguments:
;
; None.
;
; Keywords:
;
; None.
;
; Return Value:
;
; varName: A string variable containing the variable name.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetName
RETURN, self.name
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetProperty
;
; Purpose:
;
; Returns various properties of the object one at a time. This is a shorthand and
; generic way to get the value of an object's "properties", which are defined as
; the IDL variables in the object's class structure.
;
; Method Syntax:
;
; propertyValue = obj -> GetProperty(thisProperty)
;
; Auguments:
;
; thisProperty: A string variable that is equivalent to a field in the object's
; class structure. See the *__DEFINE procedure for which properties
; can be returned. The property is case insensitive.
;
; Keywords:
;
; None.
;
; Return Value:
;
; propertyValue: The value of a particular object property. Note that pointer
; properties will return the variable the pointer points to.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetProperty, thisProperty
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
; Log the error.
(self.parent -> GetProperty('ERRORLOGGER')) -> AddError
; No success finding the property requested.
RETURN, 0
ENDIF
; Get the self structure as a structure, rather than as an object.
Call_Procedure, StrLowCase(Obj_Class(self)) + '__define', classStruct
; Find the property in this class structure.
index = Where(StrPos(Tag_Names(classStruct), StrUpCase(thisProperty)) EQ 0, count)
index = index[0]
; What happened?
CASE count OF
0: Message, 'Property ' + StrUpCase(thisProperty) + ' could not be found.'
1: propertyValue = self.(index)
ELSE: Message, 'Ambiguous property. Use more characters to specify it.'
ENDCASE
; If this is a pointer, you want the thing pointed to.
IF Size(propertyValue, /TNAME) EQ 'POINTER' THEN propertyValue = *propertyValue
RETURN, propertyValue
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::GetValue
;
; Purpose:
;
; Returns the the value of the variable. That is, the variable's data.
;
; Method Syntax:
;
; varValue = GetValue(COUNT=count, OFFSET=offset, STRIDE=stride, MISSING=missing)
;
; Auguments:
;
; None.
;
; Input Keywords:
;
; COUNT: An optional vector containing the counts to be used in reading the
; variable. Count is a 1-based vector with an element for each dimension.
; The default matches the size of the variable so that all data is
; written out.
; OFFSET: An optional vector containing the starting position for the read.
; The default start position is [0, 0, ...].
; STRIDE: An optional vector containing the strides, or sampling intervals,
; between accessed values of the netCDF variable. The default stride
; vector is that for a contiguous read, [1, 1, ...].
;
; Output Keywords:
;
; ADD_OFFSET: The add_offset value for the variable, if there is one.
;
; DATATYPE: The data type of the variable, before the scale and offset are applied.
; The same as what comes back from datatype = Size(rawVariable, /TNAME).
;
; FILLVALUE: The value that is being used for the "missing" value in this variable.
;
; MISSINGINDICES: A vector containing the missing indices in the returned data. Missing
; data is identified by either the depreciated "missing_value" attribute
; or the approved "_FillValue" attribute.
;
; SCALE_FACTOR: The scale factor for the variable, if there is one.
;
; Return Value:
;
; varValue: The actual data of the variable. If scale_factor and add_offset
; attributes are present, the data is scaled and offset before it
; is returned to the caller. The "missing" data (see the MISSING
; keyword) value is not changed, although its data type might change
; in the scaling and offset process.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::GetValue, $
ADD_OFFSET=add_offset, $
COUNT=count, $
DATATYPE=datatype, $
FILLVALUE=missingvalue, $
OFFSET=offset, $
SCALE_FACTOR=scale_factor, $
STRIDE=stride, $
MISSINGINDICES=missingIndices
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
errorLogger -> AddError
RETURN, ""
ENDIF
; Read the data for this variable.
NCDF_VarGet, self.parent->GetFileID(), self.id, data, COUNT=count, OFFSET=offset, STRIDE=stride
dataType = Size(data, /TNAME)
; Does this variable contain "missing" values. If so, identify and return
; the missing data indices so they can be identified after scaling.
missingCount = 0
IF self -> HasAttr('missing_value') THEN BEGIN
missingValue = self -> GetAttrValue('missing_value')
missingIndices = Where(data EQ missingValue, missingCount)
ENDIF
IF self -> HasAttr('_FillValue') THEN BEGIN
missingValue = self -> GetAttrValue('_FillValue')
missingIndices = Where(data EQ missingValue, missingCount)
ENDIF
; If there are scale_factor and add_offset attributes defined for this variable, the
; data will be scaled and offset before it is returned. Take care to preserve missing
; values in the data. (Data type may change!)
IF (self -> HasAttr('scale_factor') OR self -> HasAttr('add_offset')) THEN BEGIN
IF self -> HasAttr('scale_factor') THEN scale_factor = self -> GetAttrValue('scale_factor') ELSE scale_factor = 1B
IF self -> HasAttr('add_offset') THEN add_offset = self -> GetAttrValue('add_offset') ELSE add_offset = 0B
data = (data * scale_factor) + add_offset
IF missingCount GT 0 THEN data[missingIndices] = missingValue
ENDIF
; Is this CHAR data? If so, convert it back to a string.
IF self.datatype EQ 'CHAR' THEN data = String(Temporary(data))
; Return the data.
RETURN, data
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::HasAttr
;
; Purpose:
;
; Indicates, by returning a 1, that this particular variable attribute is found in the ;
; file. If not found, this function returns a 0.
;
; Method Syntax:
;
; isFound = obj -> HasAttr(attrName, OBJECT=object)
;
; Auguments:
;
; attrName: The case sensitive name of a variable attribute.
;
; Keywords:
;
; OBJECT: If the attribute exists, this keyword returns the attribute's
; object reference.
;
; Return Value:
;
; isFound: If a variable attribute with this name is found, this variable
; is set to 1. It is set to 0 otherwise.
;
;------------------------------------------------------------------------------------------;
FUNCTION NCDF_Variable::HasAttr, attrName, OBJECT=object
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling.
Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /CANCEL
errorLogger = self.parent -> GetProperty('ErrorLogger')
self.errorLogger -> AddError
RETURN, ""
ENDIF
; Can you find an attribute object with this name?
object = self.attrs -> FindByName(attrName, COUNT=count)
IF count GT 0 THEN RETURN, 1 ELSE RETURN, 0
END
;------------------------------------------------------------------------------------------;
;
; NAME:
; NCDF_Variable::ParseVariable
;
; Purpose:
;
; Gathers information about the variable from the netCDF file.
;
; Method Syntax:
;
; dimObject -> ParseVariable
;
; Auguments:
;
; None.
;
; Keywords:
;
; None.
;
;------------------------------------------------------------------------------------------;
PRO NCDF_Variable::ParseVariable
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
On_Error, 2
; Gather information about the variable.
fileID = self.parent -> GetFileID()
self.id = NCDF_VarID(fileID, self.name)
varinfo = NCDF_VarInq(fileID, self.id)
self.datatype = StrUpCase(varinfo.datatype)
self.ndims = varinfo.ndims
self.nattrs = varinfo.natts
self.dims = Ptr_New(varinfo.dim)
; Get the actual dimensions of the variable.
IF self.ndims GT 0 THEN BEGIN
dimensions = LonArr(self.ndims)
dimNames = StrArr(self.ndims)
FOR j=0,self.ndims-1 DO BEGIN
NCDF_DIMINQ, fileID, (*self.dims)[j], dimName, dimSize
dimensions[j] = dimSize
dimNames[j] = dimName
ENDFOR
ENDIF ELSE BEGIN
dimensions = 0
dimNames = ""
ENDELSE
self.dimensions = Ptr_New(dimensions)
self.dimNames = Ptr_New(dimNames)
; If you have variable attributes, parse these, too.
self.attrs -> Remove, /ALL
FOR j=0,self.nattrs-1 DO BEGIN
attrName = NCDF_AttName(fileID, self.id, j)
attrObj = Obj_New('NCDF_Attribute', attrName, self.parent, VARNAME=self)
self.attrs -> Add, attrObj
ENDFOR
END
PRO NCDF_Variable::CLEANUP
Obj_Destroy, self.attrs
Ptr_Free, self.dims
Ptr_Free, self.dimensions
Ptr_Free, self.dimNames
END
FUNCTION NCDF_Variable::INIT, varName, parent, caseSensitivity = caseSensitivity
; Compiler options.
Compile_Opt DEFINT32
Compile_Opt STRICTARR
Compile_Opt STRICTARRSUBS
Compile_Opt LOGICAL_PREDICATE
; Error handling. Return 0 if can't finish.
CATCH, theError
IF theError NE 0 THEN BEGIN
CATCH, /CANCEL
errorLogger = parent -> GetProperty('ERRORLOGGER')
errorLogger -> AddError
RETURN, 0
ENDIF
; Check parameters.
IF N_Elements(varName) EQ 0 THEN Message, 'A variable name is required'
IF Size(varName, /TNAME) NE 'STRING' THEN Message, 'The variable name must be a string.'
self.name = varName
IF N_Elements(parent) EQ 0 THEN Message, 'A parent object is required.'
IF Size(parent, /TNAME) NE 'OBJREF' THEN Message, 'The parent parameter must be an object reference.'
self.parent = parent
self.attrs = Obj_New( 'NCDF_Container' )
if keyword_set( caseSensitivity ) then self.caseSensitiveAttributes = 1
; Obtain information about the variable and fill out the variable object.
self -> ParseVariable
RETURN, 1
END
PRO NCDF_Variable__DEFINE, class
class = { NCDF_VARIABLE, $
name: "", $ ; The variable name.
ID: 0L, $ ; The variable ID.
caseSensitiveAttributes: 0, $ ; Should variable attribute searches be case sensitive
dimensions: Ptr_New(), $ ; The actual dimensions of the variable.
dimNames: Ptr_New(), $ ; A vector of dimension names.
dims: Ptr_New(), $ ; The dimension IDs of the dimensions
nattrs: 0L, $ ; The number of attributes the variable has.
ndims: 0L, $ ; The number of dimensions the variable has.
datatype: "", $ ; The netCDF data byte of this variable.
parent: Obj_New(), $ ; The NCDF_FILE object where this variable resides.
attrs: Obj_New() $ ; The variable attributes (objects).
}
END
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