imax

imax( QDataSet ds ) → int

return the index of the maximum value. This is to avoid inefficient code like "where(slice.eq( max(slice) ))[0]"

Parameters

ds - rank 1 dataset

Returns:

the index of the maximum value, or -1 if the data is all fill.

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imin

imin( QDataSet ds ) → int

return the index of the minimum value. This is to avoid inefficient code like "where(slice.eq( min(slice) ))[0]"

Parameters

ds - rank 1 dataset

Returns:

the index of the maximum value, or -1 if the data is all fill.

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indgen

indgen( int len0 ) → QDataSet

returns rank 1 dataset with values [0,1,2,...] This returns an immutable dataset, so that it can be used in Jython like so: for i in indgen(200000). Note before February 2018, this would return a mutable dataset, and now this returns an IndexGenDataSet, which is immutable.

Parameters

len0 -

Returns:

org.das2.qds.QDataSet

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intarr

intarr( int len0 ) → QDataSet

create a dataset filled with zeros, stored in 4-byte ints.

Parameters

len0 - the zeroth dimension length

Returns:

rank 1 dataset filled with zeros.

See Also:

Ops_z.md#zeros(int)
Ops_d.md#dblarr(int)


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interpolateGrid

interpolateGrid( QDataSet vv, QDataSet findex0, QDataSet findex1 ) → QDataSet

interpolate values from rank 2 dataset vv using fractional indeces in rank N findex, using bilinear interpolation. Here the two rank1 indexes form a grid and the result is rank 2.

Parameters

vv - rank 2 dataset.
findex0 - rank 1 dataset of fractional indeces for the zeroth index.
findex1 - rank 1 dataset of fractional indeces for the first index.

Returns:

rank 2 dataset

See Also:

Ops_f.md#findex findex, the 1-D findex command findex, the 1-D findex command


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interpolateMod

interpolateMod( QDataSet vv, QDataSet mod, QDataSet findex ) → QDataSet

like interpolate, but the findex is recalculated when the two bracketed points are closer in the modulo space than they would be in the linear space.

Parameters

vv - rank 1 dataset that is the data to be interpolated. (e.g. longitude from 0 to 360deg)
mod - rank 0 dataset that is the mod of the space (e.g. 360deg), or rank 1 where the range is specified (e.g. -180 to 180).
findex - rank N dataset of fractional indeces. This must be dimensionless and is typically calculated by the findex command.

Returns:

the result, a rank 1 dataset with one element for each findex.

See Also:

interpolate(QDataSet,QDataSet)


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isAngleRange

isAngleRange( QDataSet ds, boolean strict ) → Double

return true if the dataset can be interpreted as radian degrees from 0 to PI or from 0 to 2*PI.

Parameters

ds - any QDataSet.
strict - return null if it's not clear that the units are degrees.

Returns:

the multiplier to make the dataset into radians, or null.

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isSafeName

isSafeName( String name ) → boolean

returns true if the name is a Java-style identifier, starting with one of a-z, A-Z, or _; followed by a-z, A-Z, 0-9, or _; and note that only ASCII characters are allowed.

Parameters

name -

Returns:

true if the name is a safe identifier name.

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