source: TI02-CSML/trunk/csml/API/genSubset.py @ 2095

Subversion URL: http://proj.badc.rl.ac.uk/svn/ndg/TI02-CSML/trunk/csml/API/genSubset.py@2095
Revision 2095, 7.4 KB checked in by domlowe, 14 years ago (diff)

more bug fixing/tidying in subsetting code
Line 
1'''#getSubset.py contains generic subsetting code that can be reused for multiple features
2Dominic Lowe, CCLRC, 31/01/2007'''
3
4import csml
5import csmlutils
6
7
8def subsetDomain(timeaxis,times, domain,**kwargs):
9    '''takes the domain and returns a subset according to the keyword selection criteria
10    time = name of time dimension
11    times = string of times
12    '''   
13    strTimes=times
14    subsetDomain={}
15    totalArraySize=1
16    for key in domain.keys():
17        straxisValues=''
18        if key in kwargs:
19            if key ==timeaxis:
20                straxisValues=strTimes
21                arraySize=len(strTimes.split())
22            elif kwargs[key][0] < kwargs[key][1]:   
23                for val in domain[key]:
24                      if val is not '':
25                            if float(val) >= kwargs[key][0]:
26                                if float(val) <= kwargs[key] [1]:
27                                    straxisValues=straxisValues+ str(val) + ','
28                straxisValues=straxisValues[:-1]
29            else:#this if deals with selections such as longitude (330,30) where the lower limit is 'greater' than the upper limit in a mathematical sense.
30                    for val in domain[key]:
31                        if val is not '':
32                            if val >= kwargs[key][0]:
33                                straxisValues=straxisValues+ str(val) + ','
34                    for val in domain[key]:
35                        if val is not '':
36                            if val <= kwargs[key] [1]:
37                                straxisValues=straxisValues+ str(val) + ','
38                    straxisValues=straxisValues[:-1]                                             
39        else: # this dimension has not been subsetted at all - CHECK  THIS
40            for val in domain[key]:
41                if val is not '':
42                    straxisValues=straxisValues+ str(val) + ','       
43            straxisValues=straxisValues[:-1]                       
44                                   
45        subsetDomain[key]=straxisValues
46        if key != timeaxis:
47            arraySize=len(subsetDomain[key].split(','))
48        else:
49            arraySize=len(subsetDomain[key].split())
50        totalArraySize = totalArraySize * arraySize
51    return subsetDomain, totalArraySize
52   
53def _setCalendar(feature, timeName):
54    '''sets the cdtime calendar needed for conversion from CSML to NetCDF'''
55    calset=False
56    for gridOrd in feature.value.gridSeriesDomain.coordTransformTable.gridOrdinates:
57        if gridOrd.coordAxisLabel.CONTENT==timeName:
58            try:
59                caltype=gridOrd.coordAxisValues.frame.split(':',1)[0]
60                calunits=gridOrd.coordAxisValues.frame.split(':',1)[1]
61                csml.csmllibs.csmltime.setcdtimeCalendar(caltype)
62                calset=True
63            except:pass
64    if calset!=True:
65        csml.csmllibs.csmltime.setcdtimeCalendar(csml.csmllibs.csmltime.cdtime.DefaultCalendar)   
66    try:
67        caltype=gridOrd.coordAxisValues.frame.split(':',1)[0]
68        calunits=gridOrd.coordAxisValues.frame.split(':',1)[1]
69        csml.csmllibs.csmltime.setcdtimeCalendar(caltype)
70    except:
71        csml.csmllibs.csmltime.setcdtimeCalendar(csml.csmllibs.csmltime.cdtime.DefaultCalendar)
72    return calunits, caltype
73
74
75def _getTimes(timeSelection, timeName, domain):
76
77    #currently supporting domain subsetting only by CRS name
78    #(but should be easy to extend later)
79    times=timeSelection
80
81    tone=csml.csmllibs.csmltime.getCDtime(times[0])
82    if len(times) == 2:
83        #then this is a range of times (t1, tn), and not a list
84        try:
85            tone=csml.csmllibs.csmltime.getCDtime(times[0])
86        except:
87            tone=times[0]
88        try:
89            ttwo=csml.csmllibs.csmltime.getCDtime(times[1])
90        except:
91            ttwo=times[1]
92        times=[]         
93        for time in domain[timeName]:
94            timeok=csml.csmllibs.csmltime.compareTimes(tone,time,ttwo)
95            if timeok ==1:
96                times.append(time)
97    return times
98
99def _getTimeToFileRatio(feature,domain, timeName):
100    if hasattr(feature.value.rangeSet, 'valueArray'):
101        if hasattr(feature.value.rangeSet.valueArray.valueComponent.quantityList, '__insertedExtract'):
102            numFiles= len( csmlutils.listify(feature.value.rangeSet.valueArray.valueComponent.quantityList.__insertedExtract.components)[0].fileList.fileNames.CONTENT.split())
103            return len(domain[timeName])/numFiles
104
105def getCoordTransformTable(domainSubset, crs):
106    cTT=csml.parser.GridCoordinatesTable()
107    ords =[]
108    for key in domainSubset.keys():
109        go=csml.parser.GridOrdinateDescription()
110        go.coordAxisLabel=csml.parser.csString(key)
111        go.gridAxesSpanned=csml.parser.csString(key)
112        go.coordAxisValues = csml.parser.SpatialOrTemporalPositionList()
113        if key==crs.axes[crs.timeAxis]:
114            go.coordAxisValues.timePositionList=csml.parser.csString(domainSubset[key]) #self.domain.key placeholder
115        else:
116            go.coordAxisValues.coordinateList=csml.parser.csString(domainSubset[key]) #self.domain.key placeholder
117        ords.append(go) #go needs a few more properties setting
118    cTT.gridOrdinates=ords
119    return cTT
120
121
122
123def getTheData(feature, selection, times,timeName):
124    domain = feature.domain
125    value=feature.value
126    files=[]
127    strTimes=''
128    fulldata=[]
129    #get the ratio of times to files
130    timeToFileRatio = _getTimeToFileRatio(feature, domain, timeName)
131       
132           
133    #list to keep track of files that have already been fetched. eg. if multiple times are in a single file only need to get data from that file once...
134    filesFetched=[]
135   
136   
137    for time in times:
138        listPosition=domain[timeName].index(time)
139        strTimes= strTimes + ' ' + time
140        for comp in csmlutils.listify(value.rangeSet.valueArray.valueComponent.quantityList.__insertedExtract.components): 
141            filePos=int(float(listPosition)/timeToFileRatio)
142            if filePos in filesFetched:
143                continue #already got data from this file, try next time
144            data=comp.getData(fileposition=filePos, **selection)
145            files.append(comp.fileList.fileNames.CONTENT[filePos]) #TODO, get the right file name
146            if fulldata ==[]:
147                fulldata = data.tolist()
148            else:
149                for item in data.tolist():
150                    fulldata.append(item)
151            filesFetched.append(filePos)
152        axisorder = data.getAxisIds()  #will need later!
153 
154    return strTimes, axisorder, fulldata
155
156def genericSubset(feature, csmlpath, ncpath, domain, kwargs):
157    if ncpath is not None:
158        pathToSubsetNetCDF=ncpath
159    else:
160        pathToSubsetNetCDF='temp.nc'
161   
162    #deal with longitude requests
163    #if the request is in -ve,+ve eg (-30,30) but the data is in (0,360) need to handle this by changing the args.
164    kwargs=csmlutils.fixLongitude(domain,kwargs)
165   
166   
167    #get the name of the time axis in the coordinate reference system
168    cat=csml.csmllibs.csmlcrs.CRSCatalogue()
169    crs=cat.getCRS(feature.value.gridSeriesDomain.srsName)
170    timeName=crs.axes[crs.timeAxis]
171     #set the reference system for the time axis
172    calunits, caltype=_setCalendar(feature, timeName)
173   
174    #selection by time - get explcit time values, not just a range mint, maxt
175    timeSelection=kwargs[timeName]
176    times=_getTimes(timeSelection, timeName,domain)
177   
178   
179    return pathToSubsetNetCDF, kwargs, timeName, calunits, caltype, times
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