org.das2.qds.SemanticOps

Common expressions that apply semantics to QDataSet. Introduced to reduce a lot of repeated code, but also to make it clear where semantics are being applied.

bounds

return the bounds DS[ JOIN_0=x,y; BINS_1=min,maxInclusive ] of the datasets independent parameters. This is only implemented for:

rank 2 Tables	extent(X),extent(Y) and Z is not represented
rank 3 array of tables	extent(X),extent(Y) and Z is not represented
rank 1 Y(X)	extent(X),extent(Y)
not for rank 2 bundle dataset
not for rank 1 bundle dataset

The zeroth dimension will be the physical dimension of the DEPEND_0 values. Or said another way:

bounds[0,0]= X min	bounds[0,1] = X max	bounds.slice(0) is the extent of X
bounds[1,0]= Y min	bounds[1,1] = Y max	bounds.slice(1) is the extent of Y

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cadenceCheck

return a dataset with 1's where the cadence following this measurement is acceptable, and 0's where there should be a break in the data. For example, here's some pseudocode:

   findex= Ops.interpolate( xds, x )
   cadenceCheck= cadenceCheck(xds)
   r= where( cadenceCheck[floor(findex)] eq 0 )
   x[r]= fill

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See Also:

checkPropertyType

verify property types. For example, that UNITS is a org.das2.datum.Units, etc. Returns true for unrecognized property names (future expansion) and null. If throwException is true, then an IllegalArgumentException is thrown.

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doubleValue

returns the Double value of the number, preserving null and NaN.

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getComponentLabels

return the labels for a dataset where DEPEND_1 is a bundle dimension. Look for the BUNDLE_1.

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getComponentNames

return the labels for a bundle dataset. For a rank 2 bundle, this will be found in BUNDLE_1, or legacy ones may have nominal data for DEPEND_1. For a rank 1 bundle this will be BUNDLE_0.

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getDependentDataSet

return the dataset that is dependent on others. For a bundle, we use DataSetOps.unbundleDefaultDataSet

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getLooseUnitsConverter

returns the UnitsConverter, or IDENTITY if the converter cannot be found and one of the two units is dimensionless.

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getPropertyType

return the property type expected for the property.

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getSimpleTableContaining

return the first table of the bundle containing x and y

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getUnitsConverter

return the UnitsConverter that will convert data from src to the units of dst.

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guessXTagWidth

return a reasonable tag width to use, or null if one cannot be guessed.

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isBins

Test for bins scheme, where BINS_1 (or BINS_0) is set. This is where a two-element index is min, max. Note the BINS dimension must be the last index of the QDataSet.

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isBundle

Test for bundle scheme. Returns true if the BUNDLE_1 is set.

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isJoin

returns true if the dataset is rank 2 or greater with the first dimension a join dimension. Note this does not return true for implicit joins, where JOIN_0 is not set.

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isLegacyBundle

See Ops.isLegacyBundle

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isMonotonic

returns true if the dataset indicates that it is monotonically increasing. See DataSetUtil.isMonotonic.

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isRank1Bundle

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isRank2Waveform

Test for rank 2 waveform dataset, where DEPEND_1 is offset from DEPEND_0, and the data is the waveform. DEPEND_1 must be at least 128 elements long. DEPEND_1 must not be dimensionless.

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isRank3JoinOfRank2Waveform

Test for rank 3 dataset that is a join of rank 2 waveform datasets.

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isSimpleBundleDataSet

returns true if the dataset is a bundle of rank 1 datasets. If no dependence is declared, it is assumed that the first one or two datasets are the independent datasets, and the last is the dependent.

    X,Y   -->  Y(X)
    X,Y,Z -->  Z(X,Y)

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isSimpleTableDataSet

returns true if the dataset is the scheme of a legacy TableDataSet with only one table. Note "Tables" have just one X unit and one Y unit, no bundles. Consider: rule about "duck typing": rules like !Ops.isBundle break this because it requires to be a simpleTable, you cannot be a bundle. LANL rich ASCII allows datasets to be both bundles and simple tables.

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isTableDataSet

returns true if the dataset is the scheme of a legacy TableDataSet

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isTimeSeries

returns true if the dataset is a time series. This is either something that has DEPEND_0 as a dataset with time location units, or a join of other datasets that are time series.

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lookupTimeLengthUnit

lookupTimeUnits

lookupUnits

weightsDataSet

return the weights dataset, possibly creating one based on VALID_MIN VALID_MAX and FILL_VALUE properties. The weights dataset will have value zero where the data is invalid, and a non-zero weight where it is valid. DataSets may also contain a weights table with relative weights, but this is not uniformly supported. Note: this uses QDataSet.WEIGHTS_PLANE Note: calls org.das2.qds.DataSetUtil.weightsDataSet.

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See Also:

xtagsDataSet

return the dataset containing the x tags for the dataset. This is QDataSet.DEPEND_0, or if that's null then IndexGenDataSet(ds.length). For a bundle, this is just the 0th dataset. For a join, this is a join of the xtags datasets of each dataset.

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ytagsDataSet

return the ytags for the simple table that is ds.

• rank 2 spectrogram: Z[X,Y] → Y
• bundle_1: ds[ :, [x,y,z] ] → y
• [x,y,z] → y

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