Пример #1
0
    def create_contexts(self):
        context_ids = []
        cond_ctxt = ParameterContext(
            'conductivity_test',
            param_type=QuantityType(value_encoding=np.float32))
        cond_ctxt.uom = 'unknown'
        cond_ctxt.fill_value = 0e0
        context_ids.append(
            self.dataset_management.create_parameter_context(
                name='conductivity_test', parameter_context=cond_ctxt.dump()))

        pres_ctxt = ParameterContext(
            'pressure_test',
            param_type=QuantityType(value_encoding=np.float32))
        pres_ctxt.uom = 'Pascal'
        pres_ctxt.fill_value = 0x0
        context_ids.append(
            self.dataset_management.create_parameter_context(
                name='pressure_test', parameter_context=pres_ctxt.dump()))

        sal_ctxt = ParameterContext(
            'salinity_test',
            param_type=QuantityType(value_encoding=np.float32))
        sal_ctxt.uom = 'PSU'
        sal_ctxt.fill_value = 0x0
        context_ids.append(
            self.dataset_management.create_parameter_context(
                name='salinity_test', parameter_context=sal_ctxt.dump()))

        temp_ctxt = ParameterContext(
            'temp_test', param_type=QuantityType(value_encoding=np.float32))
        temp_ctxt.uom = 'degree_Celsius'
        temp_ctxt.fill_value = 0e0
        context_ids.append(
            self.dataset_management.create_parameter_context(
                name='temp_test', parameter_context=temp_ctxt.dump()))

        t_ctxt = ParameterContext(
            'time_test', param_type=QuantityType(value_encoding=np.int64))
        t_ctxt.uom = 'seconds since 1970-01-01'
        t_ctxt.fill_value = 0x0
        context_ids.append(
            self.dataset_management.create_parameter_context(
                name='time_test', parameter_context=t_ctxt.dump()))

        return context_ids
Пример #2
0
    def _create_input_param_dict_for_test(self, parameter_dict_name=''):

        pdict = ParameterDictionary()

        t_ctxt = ParameterContext(
            'time',
            param_type=QuantityType(value_encoding=numpy.dtype('float64')))
        t_ctxt.axis = AxisTypeEnum.TIME
        t_ctxt.uom = 'seconds since 01-01-1900'
        pdict.add_context(t_ctxt)

        cond_ctxt = ParameterContext(
            'conductivity',
            param_type=QuantityType(value_encoding=numpy.dtype('float32')))
        cond_ctxt.uom = ''
        pdict.add_context(cond_ctxt)

        pres_ctxt = ParameterContext(
            'pressure',
            param_type=QuantityType(value_encoding=numpy.dtype('float32')))
        pres_ctxt.uom = ''
        pdict.add_context(pres_ctxt)

        temp_ctxt = ParameterContext(
            'temperature',
            param_type=QuantityType(value_encoding=numpy.dtype('float32')))
        temp_ctxt.uom = ''
        pdict.add_context(temp_ctxt)

        dens_ctxt = ParameterContext(
            'density',
            param_type=QuantityType(value_encoding=numpy.dtype('float32')))
        dens_ctxt.uom = ''
        pdict.add_context(dens_ctxt)

        sal_ctxt = ParameterContext(
            'salinity',
            param_type=QuantityType(value_encoding=numpy.dtype('float32')))
        sal_ctxt.uom = ''
        pdict.add_context(sal_ctxt)

        #create temp streamdef so the data product can create the stream
        pc_list = []
        for pc_k, pc in pdict.iteritems():
            ctxt_id = self.dataset_management.create_parameter_context(
                pc_k, pc[1].dump())
            pc_list.append(ctxt_id)
            self.addCleanup(self.dataset_management.delete_parameter_context,
                            ctxt_id)

        pdict_id = self.dataset_management.create_parameter_dictionary(
            parameter_dict_name, pc_list)
        self.addCleanup(self.dataset_management.delete_parameter_dictionary,
                        pdict_id)

        return pdict_id
    def __init__(self,
                 total_domain=(10, 10),
                 brick_size=5,
                 use_hdf=False,
                 root_dir='test_data/multi_dim_trials',
                 guid=None,
                 dtype='int16'):
        self.total_domain = total_domain
        self.brick_sizes = tuple(brick_size for x in total_domain)
        self.use_hdf = use_hdf
        self.dtype = np.dtype(dtype).name
        if self.use_hdf:
            self.guid = guid or create_guid()
            name = '%s_%s' % (self.guid, self.dtype)
            self.root_dir = root_dir
            if not os.path.exists(self.root_dir):
                os.makedirs(self.root_dir)

            if os.path.exists(os.path.join(self.root_dir, name)):
                shutil.rmtree(os.path.join(self.root_dir, name))

            self.master_manager = MasterManager(
                self.root_dir, name, name='md_test_{0}'.format(name))

            self.master_manager.flush()

            pc = ParameterContext('test_param',
                                  param_type=QuantityType(self.dtype),
                                  fill_value=-1)
            self.param_manager = ParameterManager(
                os.path.join(self.root_dir, name, pc.name), pc.name)
            self.param_manager.parameter_context = pc
            self.master_manager.create_group(pc.name)

            self.param_manager.flush()

        self.bricks = {}

        self.brick_origins = bricking_utils.calc_brick_origins(
            self.total_domain, self.brick_sizes)
        self.brick_extents, self.rtree_extents = bricking_utils.calc_brick_and_rtree_extents(
            self.brick_origins, self.brick_sizes)
        self.build_bricks()

        self.rtree = RTreeProxy()
        for x in BrickingAssessor.rtree_populator(self.rtree_extents,
                                                  self.brick_extents):
            self.rtree.insert(*x)
Пример #4
0
    def rdt_to_granule(self, context, value_array, comp_val=None):
        time = ParameterContext(
            name='time', param_type=QuantityType(value_encoding=np.float64))

        pdict = ParameterDictionary()
        pdict.add_context(time, is_temporal=True)
        pdict.add_context(context)

        rdt = RecordDictionaryTool(param_dictionary=pdict)
        rdt['time'] = np.arange(len(value_array))
        rdt['test'] = value_array

        granule = rdt.to_granule()
        rdt2 = RecordDictionaryTool.load_from_granule(granule)

        testval = comp_val if comp_val is not None else value_array
        actual = rdt2['test']

        if isinstance(testval, basestring):
            self.assertEquals(testval, actual)
        else:
            np.testing.assert_array_equal(testval, actual)
Пример #5
0
    def cov_io(self, context, value_array, comp_val=None):
        pdict = ParameterDictionary()
        time = ParameterContext(
            name='time', param_type=QuantityType(value_encoding=np.float64))
        pdict.add_context(context)
        pdict.add_context(time, True)
        # Construct temporal and spatial Coordinate Reference System objects
        tcrs = CRS([AxisTypeEnum.TIME])
        scrs = CRS([AxisTypeEnum.LON, AxisTypeEnum.LAT])

        # Construct temporal and spatial Domain objects
        tdom = GridDomain(GridShape('temporal', [0]), tcrs,
                          MutabilityEnum.EXTENSIBLE)  # 1d (timeline)
        sdom = GridDomain(GridShape('spatial',
                                    [0]), scrs, MutabilityEnum.IMMUTABLE
                          )  # 0d spatial topology (station/trajectory)

        # Instantiate the SimplexCoverage providing the ParameterDictionary, spatial Domain and temporal Domain
        cov = SimplexCoverage('test_data',
                              create_guid(),
                              'sample coverage_model',
                              parameter_dictionary=pdict,
                              temporal_domain=tdom,
                              spatial_domain=sdom)
        self.addCleanup(shutil.rmtree, cov.persistence_dir)

        cov.insert_timesteps(len(value_array))
        cov.set_parameter_values('test',
                                 tdoa=slice(0, len(value_array)),
                                 value=value_array)
        comp_val = comp_val if comp_val is not None else value_array
        testval = cov.get_parameter_values('test')
        try:
            np.testing.assert_array_equal(testval, comp_val)
        except:
            print repr(value_array)
            raise
Пример #6
0
    def _get_pdict(self, filter_values):
        t_ctxt = ParameterContext(
            'TIME', param_type=QuantityType(value_encoding=np.dtype('int64')))
        t_ctxt.uom = 'seconds since 01-01-1900'
        t_ctxt_id = self.dataset_management.create_parameter_context(
            name='TIME',
            parameter_context=t_ctxt.dump(),
            parameter_type='quantity<int64>',
            unit_of_measure=t_ctxt.uom)

        lat_ctxt = ParameterContext(
            'LAT',
            param_type=ConstantType(
                QuantityType(value_encoding=np.dtype('float32'))),
            fill_value=-9999)
        lat_ctxt.axis = AxisTypeEnum.LAT
        lat_ctxt.uom = 'degree_north'
        lat_ctxt_id = self.dataset_management.create_parameter_context(
            name='LAT',
            parameter_context=lat_ctxt.dump(),
            parameter_type='quantity<float32>',
            unit_of_measure=lat_ctxt.uom)

        lon_ctxt = ParameterContext(
            'LON',
            param_type=ConstantType(
                QuantityType(value_encoding=np.dtype('float32'))),
            fill_value=-9999)
        lon_ctxt.axis = AxisTypeEnum.LON
        lon_ctxt.uom = 'degree_east'
        lon_ctxt_id = self.dataset_management.create_parameter_context(
            name='LON',
            parameter_context=lon_ctxt.dump(),
            parameter_type='quantity<float32>',
            unit_of_measure=lon_ctxt.uom)

        # Independent Parameters
        # Temperature - values expected to be the decimal results of conversion from hex
        temp_ctxt = ParameterContext(
            'TEMPWAT_L0',
            param_type=QuantityType(value_encoding=np.dtype('float32')),
            fill_value=-9999)
        temp_ctxt.uom = 'deg_C'
        temp_ctxt_id = self.dataset_management.create_parameter_context(
            name='TEMPWAT_L0',
            parameter_context=temp_ctxt.dump(),
            parameter_type='quantity<float32>',
            unit_of_measure=temp_ctxt.uom)

        # Conductivity - values expected to be the decimal results of conversion from hex
        cond_ctxt = ParameterContext(
            'CONDWAT_L0',
            param_type=QuantityType(value_encoding=np.dtype('float32')),
            fill_value=-9999)
        cond_ctxt.uom = 'S m-1'
        cond_ctxt_id = self.dataset_management.create_parameter_context(
            name='CONDWAT_L0',
            parameter_context=cond_ctxt.dump(),
            parameter_type='quantity<float32>',
            unit_of_measure=cond_ctxt.uom)

        # Pressure - values expected to be the decimal results of conversion from hex
        press_ctxt = ParameterContext(
            'PRESWAT_L0',
            param_type=QuantityType(value_encoding=np.dtype('float32')),
            fill_value=-9999)
        press_ctxt.uom = 'dbar'
        press_ctxt_id = self.dataset_management.create_parameter_context(
            name='PRESWAT_L0',
            parameter_context=press_ctxt.dump(),
            parameter_type='quantity<float32>',
            unit_of_measure=press_ctxt.uom)

        # Dependent Parameters

        # TEMPWAT_L1 = (TEMPWAT_L0 / 10000) - 10
        tl1_func = '(T / 10000) - 10'
        tl1_pmap = {'T': 'TEMPWAT_L0'}
        expr = NumexprFunction('TEMPWAT_L1',
                               tl1_func, ['T'],
                               param_map=tl1_pmap)
        tempL1_ctxt = ParameterContext(
            'TEMPWAT_L1',
            param_type=ParameterFunctionType(function=expr),
            variability=VariabilityEnum.TEMPORAL)
        tempL1_ctxt.uom = 'deg_C'
        tempL1_ctxt_id = self.dataset_management.create_parameter_context(
            name=tempL1_ctxt.name,
            parameter_context=tempL1_ctxt.dump(),
            parameter_type='pfunc',
            unit_of_measure=tempL1_ctxt.uom)

        # CONDWAT_L1 = (CONDWAT_L0 / 100000) - 0.5
        cl1_func = '(C / 100000) - 0.5'
        cl1_pmap = {'C': 'CONDWAT_L0'}
        expr = NumexprFunction('CONDWAT_L1',
                               cl1_func, ['C'],
                               param_map=cl1_pmap)
        condL1_ctxt = ParameterContext(
            'CONDWAT_L1',
            param_type=ParameterFunctionType(function=expr),
            variability=VariabilityEnum.TEMPORAL)
        condL1_ctxt.uom = 'S m-1'
        condL1_ctxt_id = self.dataset_management.create_parameter_context(
            name=condL1_ctxt.name,
            parameter_context=condL1_ctxt.dump(),
            parameter_type='pfunc',
            unit_of_measure=condL1_ctxt.uom)

        # Equation uses p_range, which is a calibration coefficient - Fixing to 679.34040721
        #   PRESWAT_L1 = (PRESWAT_L0 * p_range / (0.85 * 65536)) - (0.05 * p_range)
        pl1_func = '(P * p_range / (0.85 * 65536)) - (0.05 * p_range)'
        pl1_pmap = {'P': 'PRESWAT_L0', 'p_range': 679.34040721}
        expr = NumexprFunction('PRESWAT_L1',
                               pl1_func, ['P', 'p_range'],
                               param_map=pl1_pmap)
        presL1_ctxt = ParameterContext(
            'PRESWAT_L1',
            param_type=ParameterFunctionType(function=expr),
            variability=VariabilityEnum.TEMPORAL)
        presL1_ctxt.uom = 'S m-1'
        presL1_ctxt_id = self.dataset_management.create_parameter_context(
            name=presL1_ctxt.name,
            parameter_context=presL1_ctxt.dump(),
            parameter_type='pfunc',
            unit_of_measure=presL1_ctxt.uom)

        # Density & practical salinity calucluated using the Gibbs Seawater library - available via python-gsw project:
        #       https://code.google.com/p/python-gsw/ & http://pypi.python.org/pypi/gsw/3.0.1

        # PRACSAL = gsw.SP_from_C((CONDWAT_L1 * 10), TEMPWAT_L1, PRESWAT_L1)
        owner = 'gsw'
        sal_func = 'SP_from_C'
        sal_arglist = ['C', 't', 'p']
        sal_pmap = {
            'C':
            NumexprFunction('CONDWAT_L1*10',
                            'C*10', ['C'],
                            param_map={'C': 'CONDWAT_L1'}),
            't':
            'TEMPWAT_L1',
            'p':
            'PRESWAT_L1'
        }
        sal_kwargmap = None
        expr = PythonFunction('PRACSAL', owner, sal_func, sal_arglist,
                              sal_kwargmap, sal_pmap)
        sal_ctxt = ParameterContext('PRACSAL',
                                    param_type=ParameterFunctionType(expr),
                                    variability=VariabilityEnum.TEMPORAL)
        sal_ctxt.uom = 'g kg-1'
        sal_ctxt_id = self.dataset_management.create_parameter_context(
            name=sal_ctxt.name,
            parameter_context=sal_ctxt.dump(),
            parameter_type='pfunc',
            unit_of_measure=sal_ctxt.uom)

        # absolute_salinity = gsw.SA_from_SP(PRACSAL, PRESWAT_L1, longitude, latitude)
        # conservative_temperature = gsw.CT_from_t(absolute_salinity, TEMPWAT_L1, PRESWAT_L1)
        # DENSITY = gsw.rho(absolute_salinity, conservative_temperature, PRESWAT_L1)
        owner = 'gsw'
        abs_sal_expr = PythonFunction('abs_sal', owner, 'SA_from_SP',
                                      ['PRACSAL', 'PRESWAT_L1', 'LON', 'LAT'])
        cons_temp_expr = PythonFunction(
            'cons_temp', owner, 'CT_from_t',
            [abs_sal_expr, 'TEMPWAT_L1', 'PRESWAT_L1'])
        dens_expr = PythonFunction(
            'DENSITY', owner, 'rho',
            [abs_sal_expr, cons_temp_expr, 'PRESWAT_L1'])
        dens_ctxt = ParameterContext(
            'DENSITY',
            param_type=ParameterFunctionType(dens_expr),
            variability=VariabilityEnum.TEMPORAL)
        dens_ctxt.uom = 'kg m-3'
        dens_ctxt_id = self.dataset_management.create_parameter_context(
            name=dens_ctxt.name,
            parameter_context=dens_ctxt.dump(),
            parameter_type='pfunc',
            unit_of_measure=dens_ctxt.uom)

        ids = [
            t_ctxt_id, lat_ctxt_id, lon_ctxt_id, temp_ctxt_id, cond_ctxt_id,
            press_ctxt_id, tempL1_ctxt_id, condL1_ctxt_id, presL1_ctxt_id,
            sal_ctxt_id, dens_ctxt_id
        ]
        contexts = [
            t_ctxt, lat_ctxt, lon_ctxt, temp_ctxt, cond_ctxt, press_ctxt,
            tempL1_ctxt, condL1_ctxt, presL1_ctxt, sal_ctxt, dens_ctxt
        ]
        context_ids = [
            ids[i] for i, ctxt in enumerate(contexts)
            if ctxt.name in filter_values
        ]
        pdict_name = '_'.join(
            [ctxt.name for ctxt in contexts if ctxt.name in filter_values])

        try:
            self.pdicts[pdict_name]
            return self.pdicts[pdict_name]
        except KeyError:
            pdict_id = self.dataset_management.create_parameter_dictionary(
                pdict_name,
                parameter_context_ids=context_ids,
                temporal_context='time')
            self.pdicts[pdict_name] = pdict_id
            return pdict_id
Пример #7
0
    def create_pfuncs(self):
        contexts = {}
        funcs = {}

        t_ctxt = ParameterContext(
            'TIME', param_type=QuantityType(value_encoding=np.dtype('int64')))
        t_ctxt.uom = 'seconds since 01-01-1900'
        t_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_TIME', parameter_context=t_ctxt.dump())
        contexts['TIME'] = (t_ctxt, t_ctxt_id)

        lat_ctxt = ParameterContext(
            'LAT',
            param_type=ConstantType(
                QuantityType(value_encoding=np.dtype('float32'))),
            fill_value=-9999)
        lat_ctxt.axis = AxisTypeEnum.LAT
        lat_ctxt.uom = 'degree_north'
        lat_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_LAT', parameter_context=lat_ctxt.dump())
        contexts['LAT'] = lat_ctxt, lat_ctxt_id

        lon_ctxt = ParameterContext(
            'LON',
            param_type=ConstantType(
                QuantityType(value_encoding=np.dtype('float32'))),
            fill_value=-9999)
        lon_ctxt.axis = AxisTypeEnum.LON
        lon_ctxt.uom = 'degree_east'
        lon_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_LON', parameter_context=lon_ctxt.dump())
        contexts['LON'] = lon_ctxt, lon_ctxt_id

        # Independent Parameters

        # Temperature - values expected to be the decimal results of conversion from hex
        temp_ctxt = ParameterContext(
            'TEMPWAT_L0',
            param_type=QuantityType(value_encoding=np.dtype('float32')),
            fill_value=-9999)
        temp_ctxt.uom = 'deg_C'
        temp_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_TEMPWAT_L0', parameter_context=temp_ctxt.dump())
        contexts['TEMPWAT_L0'] = temp_ctxt, temp_ctxt_id

        # Conductivity - values expected to be the decimal results of conversion from hex
        cond_ctxt = ParameterContext(
            'CONDWAT_L0',
            param_type=QuantityType(value_encoding=np.dtype('float32')),
            fill_value=-9999)
        cond_ctxt.uom = 'S m-1'
        cond_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_CONDWAT_L0', parameter_context=cond_ctxt.dump())
        contexts['CONDWAT_L0'] = cond_ctxt, cond_ctxt_id

        # Pressure - values expected to be the decimal results of conversion from hex
        press_ctxt = ParameterContext(
            'PRESWAT_L0',
            param_type=QuantityType(value_encoding=np.dtype('float32')),
            fill_value=-9999)
        press_ctxt.uom = 'dbar'
        press_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_PRESWAT_L0', parameter_context=press_ctxt.dump())
        contexts['PRESWAT_L0'] = press_ctxt, press_ctxt_id

        # Dependent Parameters

        # TEMPWAT_L1 = (TEMPWAT_L0 / 10000) - 10
        tl1_func = '(T / 10000) - 10'
        expr = NumexprFunction('TEMPWAT_L1', tl1_func, ['T'])
        expr_id = self.dataset_management.create_parameter_function(
            name='test_TEMPWAT_L1', parameter_function=expr.dump())
        funcs['TEMPWAT_L1'] = expr, expr_id

        tl1_pmap = {'T': 'TEMPWAT_L0'}
        expr.param_map = tl1_pmap
        tempL1_ctxt = ParameterContext(
            'TEMPWAT_L1',
            param_type=ParameterFunctionType(function=expr),
            variability=VariabilityEnum.TEMPORAL)
        tempL1_ctxt.uom = 'deg_C'
        tempL1_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_TEMPWAT_L1',
            parameter_context=tempL1_ctxt.dump(),
            parameter_function_id=expr_id)
        contexts['TEMPWAT_L1'] = tempL1_ctxt, tempL1_ctxt_id

        # CONDWAT_L1 = (CONDWAT_L0 / 100000) - 0.5
        cl1_func = '(C / 100000) - 0.5'
        expr = NumexprFunction('CONDWAT_L1', cl1_func, ['C'])
        expr_id = self.dataset_management.create_parameter_function(
            name='test_CONDWAT_L1', parameter_function=expr.dump())
        funcs['CONDWAT_L1'] = expr, expr_id

        cl1_pmap = {'C': 'CONDWAT_L0'}
        expr.param_map = cl1_pmap
        condL1_ctxt = ParameterContext(
            'CONDWAT_L1',
            param_type=ParameterFunctionType(function=expr),
            variability=VariabilityEnum.TEMPORAL)
        condL1_ctxt.uom = 'S m-1'
        condL1_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_CONDWAT_L1',
            parameter_context=condL1_ctxt.dump(),
            parameter_function_id=expr_id)
        contexts['CONDWAT_L1'] = condL1_ctxt, condL1_ctxt_id

        # Equation uses p_range, which is a calibration coefficient - Fixing to 679.34040721
        #   PRESWAT_L1 = (PRESWAT_L0 * p_range / (0.85 * 65536)) - (0.05 * p_range)
        pl1_func = '(P * p_range / (0.85 * 65536)) - (0.05 * p_range)'
        expr = NumexprFunction('PRESWAT_L1', pl1_func, ['P', 'p_range'])
        expr_id = self.dataset_management.create_parameter_function(
            name='test_PRESWAT_L1', parameter_function=expr.dump())
        funcs['PRESWAT_L1'] = expr, expr_id

        pl1_pmap = {'P': 'PRESWAT_L0', 'p_range': 679.34040721}
        expr.param_map = pl1_pmap
        presL1_ctxt = ParameterContext(
            'PRESWAT_L1',
            param_type=ParameterFunctionType(function=expr),
            variability=VariabilityEnum.TEMPORAL)
        presL1_ctxt.uom = 'S m-1'
        presL1_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_CONDWAT_L1',
            parameter_context=presL1_ctxt.dump(),
            parameter_function_id=expr_id)
        contexts['PRESWAT_L1'] = presL1_ctxt, presL1_ctxt_id

        # Density & practical salinity calucluated using the Gibbs Seawater library - available via python-gsw project:
        #       https://code.google.com/p/python-gsw/ & http://pypi.python.org/pypi/gsw/3.0.1

        # PRACSAL = gsw.SP_from_C((CONDWAT_L1 * 10), TEMPWAT_L1, PRESWAT_L1)
        owner = 'gsw'
        sal_func = 'SP_from_C'
        sal_arglist = ['C', 't', 'p']
        expr = PythonFunction('PRACSAL', owner, sal_func, sal_arglist)
        expr_id = self.dataset_management.create_parameter_function(
            name='test_PRACSAL', parameter_function=expr.dump())
        funcs['PRACSAL'] = expr, expr_id

        # A magic function that may or may not exist actually forms the line below at runtime.
        sal_pmap = {
            'C':
            NumexprFunction('CONDWAT_L1*10',
                            'C*10', ['C'],
                            param_map={'C': 'CONDWAT_L1'}),
            't':
            'TEMPWAT_L1',
            'p':
            'PRESWAT_L1'
        }
        expr.param_map = sal_pmap
        sal_ctxt = ParameterContext('PRACSAL',
                                    param_type=ParameterFunctionType(expr),
                                    variability=VariabilityEnum.TEMPORAL)
        sal_ctxt.uom = 'g kg-1'
        sal_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_PRACSAL',
            parameter_context=sal_ctxt.dump(),
            parameter_function_id=expr_id)
        contexts['PRACSAL'] = sal_ctxt, sal_ctxt_id

        # absolute_salinity = gsw.SA_from_SP(PRACSAL, PRESWAT_L1, longitude, latitude)
        # conservative_temperature = gsw.CT_from_t(absolute_salinity, TEMPWAT_L1, PRESWAT_L1)
        # DENSITY = gsw.rho(absolute_salinity, conservative_temperature, PRESWAT_L1)
        owner = 'gsw'
        abs_sal_expr = PythonFunction('abs_sal', owner, 'SA_from_SP',
                                      ['PRACSAL', 'PRESWAT_L1', 'LON', 'LAT'])
        cons_temp_expr = PythonFunction(
            'cons_temp', owner, 'CT_from_t',
            [abs_sal_expr, 'TEMPWAT_L1', 'PRESWAT_L1'])
        dens_expr = PythonFunction(
            'DENSITY', owner, 'rho',
            [abs_sal_expr, cons_temp_expr, 'PRESWAT_L1'])
        dens_ctxt = ParameterContext(
            'DENSITY',
            param_type=ParameterFunctionType(dens_expr),
            variability=VariabilityEnum.TEMPORAL)
        dens_ctxt.uom = 'kg m-3'
        dens_ctxt_id = self.dataset_management.create_parameter_context(
            name='test_DENSITY', parameter_context=dens_ctxt.dump())
        contexts['DENSITY'] = dens_ctxt, dens_ctxt_id
        return contexts, funcs