## org.das2.qds.ops.Ops

A fairly complete set of operations for QDataSets, including binary operations like "add" and "subtract", but also more abstract (and complex) operations like smooth and fftPower. Most operations check data units and validity, but consult the documentation for each function. These operations are all available in Jython scripts, and some, like add, are connected to operator symbols like +.

## PI

closest double to π or TAU/2

## TAU

closest double to τ or 2*PI

## E

the closest double to e, the base of natural logarithms.

## abs

abs( QDataSet ds1 ) → QDataSet

element-wise abs. For vectors, this returns the length of each element. Note Jython conflict needs to be resolved. Note the result of this will have dimensionless units, and see magnitude for the more abstract operator. For ratio-type units (Stevens) like "kms", the unit is preserved.

### Parameters

ds1 - the dataset

### Returns:

dataset with the same geometry

### See Also:

Ops#magnitude(QDataSet) magnitude(ds), which preserves the sign.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## abs

abs( long x ) → long

return the abs of the long, to support Jython properly.

### Parameters

x - the long

### Returns:

abs of the long
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## abs

abs( double v ) → double

return the abs of the double, to support Jython properly.

### Parameters

v - the valye

### Returns:

abs of the value
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## abs

abs( Object ds1 ) → QDataSet

promote the list, double, array etc to QDataSet before taking abs.

### Parameters

ds1 - list, double, array, etc

### Returns:

the abs in a QDataSet
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## accum

accum( QDataSet accumDs, QDataSet ds ) → QDataSet

return an array that is the running sum of each element in the array, starting with the value accum.
Result[i]= accum + total( ds[0:i] ) + ds[i]
If a fill value is encountered, then zero is added to the accumulation.

### Parameters

accumDs - the initial value of the running sum. Last value of Rank 0 or Rank 1 dataset is used, or may be null.
ds - each element is added to the running sum

### Returns:

the running of each element in the array.

### See Also:

diff(QDataSet)
[search for examples] [view on GitHub] [view on old javadoc] [view source]
accum( Object accumDs, Object ds ) → QDataSet [view source]

## accum

accum( QDataSet ds ) → QDataSet

return an array that is the running sum of each element in the array, starting with the value accum. Result[i]= total( ds[0:i+1] )

### Parameters

ds - each element is added to the running sum

### Returns:

the running of each element in the array.

### See Also:

diff(QDataSet)
[search for examples] [view on GitHub] [view on old javadoc] [view source]
accum( Object ds ) → QDataSet [view source]

## acos

acos( QDataSet ds ) → QDataSet

element-wise arccos, the inverse of the cos function.

### Parameters

ds - the values

### Returns:

the angles for the values in radians

### See Also:

Math#acos(double)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## acos

acos( double ds ) → double

return the acos of the real number in radians.

### Parameters

ds - the cos of the angle

### Returns:

the angle in radians
[search for examples] [view on GitHub] [view on old javadoc] [view source]
acos( Object ds ) → QDataSet [view source]

## add

add( QDataSet ds1, QDataSet ds2 ) → QDataSet

add the two datasets which have the compatible geometry and units. For example,

>     ds1=timegen('2014-10-15T07:23','60s',300)
>     ds2=dataset('30s')
>     print add(ds1,ds2)

The units handling is quite simple, and this will soon change. Note that the Jython operator + is overloaded to this method.

### Parameters

ds1 - a rank N dataset
ds2 - a rank M dataset with compatible geometry

### Returns:

the element-wise sum of the two datasets.

### See Also:

addGen(QDataSet, QDataSet, java.util.Map) addGen, which shows how units are resolved.
https://sourceforge.net/p/autoplot/bugs/2558/,
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## add

add( Object ds1, Object ds2 ) → QDataSet

add the two datasets which have the compatible geometry and units.

### Parameters

ds1 - QDataSet, array, string, scalar argument
ds2 - QDataSet, array, string, scalar argument with compatible geometry.

### Returns:

the element-wise sum of the two datasets.

### See Also:

dataset(java.lang.Object)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## add

add( QDataSet ds1, QDataSet ds2, QDataSet ds3 ) → QDataSet

three-argument add is provided as a convenience for environments (like Java and the Mash-up tool in Autoplot) where add is not an in-fix operator. For example, when taking the magnitude this allows for sqrt( add( pow( ds1,2), pow( ds2,2), pow( ds3,2) ) ) which is more readable than sqrt( add( add( pow( ds1,2), pow( ds2,2) ), pow( ds3,2) ) ) )

### Parameters

ds1 - a rank N dataset
ds2 - a rank N dataset or one with compatible geometry
ds3 - a rank N dataset or one with compatible geometry

### Returns:

the sum
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## and

and( QDataSet ds1, QDataSet ds2 ) → QDataSet

element-wise logical and function. non-zero is true, zero is false.

### Parameters

ds1 - a QDataSet
ds2 - a QDataSet

### Returns:

a QDataSet

### See Also:

bitwiseAnd(QDataSet, QDataSet)
[search for examples] [view on GitHub] [view on old javadoc] [view source]
and( Object ds1, Object ds2 ) → QDataSet [view source]

## append

append( QDataSet ds1, QDataSet ds2 ) → QDataSet

append two datasets that are QUBEs. DEPEND_0 and other metadata is handled as well. So for example:

>     ds1= findgen(10)
>     ds2= findgen(12)
>     print append(ds1,ds2)  ; dataSet[22] (dimensionless)

If both datasets are ArrayDataSets and of the same component type, then the result will have this type as well. Otherwise DDataSet is returned.

### Parameters

ds1 - null or rank N dataset
ds2 - rank N dataset with compatible geometry.

### Returns:

a QDataSet

### See Also:

concatenate(QDataSet, QDataSet) which is the same thing.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## appendEvents

Deprecated: since append works with events datasets.

## applyBinaryOp

applyBinaryOp( QDataSet ds1, QDataSet ds2, org.das2.qds.ops.Ops.BinaryOp op ) → org.das2.qds.MutablePropertyDataSet

apply the binary operator element-for-element of the two datasets, minding dataset geometry, fill values, etc. The two datasets are coerced to compatible geometry, if possible (e.g.Temperature[Time]+2deg), using CoerceUtil.coerce. Structural metadata such as DEPEND_0 are preserved where this is reasonable, and dimensional metadata such as UNITS are dropped.

### Parameters

ds1 - the first argument
ds2 - the second argument
op - binary operation for each pair of elements

### Returns:

the result with the same geometry as the pair.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyBinaryOp

applyBinaryOp( Object ds1, Object ds2, org.das2.qds.ops.Ops.BinaryOp op ) → org.das2.qds.MutablePropertyDataSet

As with applyBinaryOp, but promote compatible objects to QDataSet first.

### Parameters

ds1 - the first operand
ds2 - the second operand
op - binary operation for each pair of elements

### Returns:

the result with the same geometry as the pair.

### See Also:

dataset(java.lang.Object)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyIndex

applyIndex( QDataSet vv, QDataSet ds, Number fillValue ) → org.das2.qds.WritableDataSet

apply the indices, checking for out-of-bounds values.

### Parameters

vv - values to return, a rank 1, N-element dataset.
ds - the indices.
fillValue - the value to use when the index is out-of-bounds.

### Returns:

data a dataset with the geometry of ds and the units of values.

### See Also:

subset(QDataSet, QDataSet) subset, which does the same thing.
applyIndex(QDataSet, int, QDataSet)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyIndex

applyIndex( QDataSet ds, QDataSet r ) → org.das2.qds.WritableDataSet

apply the indices to the dataset, resorting the 0th dimension using the indices of r.

### Parameters

ds - values to return, a rank 1 N-element dataset, or rank 2 N by m element dataset.
r - the indices.

### Returns:

data a dataset with the geometry of ds and the units of values.

### See Also:

subset(QDataSet, QDataSet) subset, which does the same thing.
applyIndex(QDataSet, int, QDataSet)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyIndex

applyIndex( Object dso, QDataSet r ) → org.das2.qds.WritableDataSet

apply the indices

### Parameters

dso - values to return, a rank 1, N-element dataset.
r - the indices.

### Returns:

data a dataset with the geometry of ds and the units of values.

### See Also:

applyIndex(QDataSet, int, QDataSet)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyIndex

applyIndex( QDataSet ds, int dimension, QDataSet indices ) → org.das2.qds.MutablePropertyDataSet

apply the indices to the given dimension.

### Parameters

ds - rank N qube of data.
dimension - the dimension on which the indices should be applied.
indices - the indices to apply.

### Returns:

the data with in indices applied.

### See Also:

https://github.com/autoplot/dev/blob/master/demos/2023/20230909/demoApplyIndex.jy
SubsetDataSet
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyUnaryOp

applyUnaryOp( QDataSet ds1, org.das2.qds.ops.Ops.UnaryOp op ) → org.das2.qds.MutablePropertyDataSet

apply the unary operation (such as "cos") to the dataset, propagating DEPEND_0 through DEPEND_3 and other appropriate metadata.

### Parameters

ds1 - the argument
op - the operation for each element.

### Returns:

the result the the same geometry.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## applyUnaryOp

applyUnaryOp( Object ds1, org.das2.qds.ops.Ops.UnaryOp op ) → org.das2.qds.MutablePropertyDataSet

apply the unary operation (such as "cos") to the dataset, propagating DEPEND_0 through DEPEND_3 and other appropriate metadata.

### Parameters

ds1 - the argument which can be converted to a dataset.
op - the operation for each element.

### Returns:

the result the the same geometry.
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## arange

arange( int len0 ) → QDataSet

returns rank 1 dataset with values [0.,1.,2.,...]

### Parameters

len0 - an int

### Returns:

a rank 1 dataset
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## arraySplit

arraySplit( QDataSet ds, int sections ) → QDataSet

reproduce NumPy array_split function, which divides rank 1 data into a rank 2 dataset with `sections` sections. When the data is not evenly divisible into so many sections, having remainder R, the extra elements will be found in the first R segments.

### Parameters

ds - the rank 1 data.
sections - number of sections

### Returns:

rank 2 non-qube array
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## arraySplit

arraySplit( QDataSet ds, QDataSet divisions ) → QDataSet

reproduce NumPy array_split function, which divides rank 1 data into a rank 2 dataset with divisions at the given divisions.

### Parameters

ds - the rank 1 data.
divisions - index of each new section, first 0 is implicit.

### Returns:

rank 2 non-qube array
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## arraySplit

arraySplit( QDataSet ds, int[] divisions ) → QDataSet

reproduce NumPy array_split function, which divides rank 1 data into a rank 2 dataset with divisions at the given divisions.

### Parameters

ds - the rank 1 data.
divisions - index of each new section, first 0 is implicit.

### Returns:

rank 2 non-qube array
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## asin

asin( QDataSet ds ) → QDataSet

element-wise arcsin, the inverse of the sin function.

### Parameters

ds - the values

### Returns:

the angles for the values in radians

### See Also:

Math#asin(double)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## asin

asin( double ds ) → double

return the asin of the real number in radians.

### Parameters

ds - the sin of the angle

### Returns:

the angle in radians
[search for examples] [view on GitHub] [view on old javadoc] [view source]
asin( Object ds ) → QDataSet [view source]

## atan

atan( QDataSet ds ) → QDataSet

element-wise arc tangent function

### Parameters

ds - the values

### Returns:

the angles in radians

### See Also:

Math#atan(double)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## atan

atan( double ds ) → double

arc tangent function

### Parameters

ds - the value

### Returns:

the angle in radians

### See Also:

Math#atan(double)
[search for examples] [view on GitHub] [view on old javadoc] [view source]
atan( Object ds ) → QDataSet [view source]

## atan2

atan2( QDataSet y, QDataSet x ) → QDataSet

element-wise atan2, 4-quadrant atan. From the Java atan2 documentation: "Returns the angle theta from the conversion of rectangular coordinates ( x, y) to polar coordinates (r, theta). This method computes the phase theta by computing an arc tangent of y/x in the range of -pi to pi."

Note different languages have different argument order. Microsoft Office uses atan2(x,y); IDL uses atan(y,x); Matlab uses atan2(y,x); and NumPy uses arctan2(y,x).

### Parameters

y - the y values
x - the x values

### Returns:

angles between -PI and PI

### See Also:

java.lang.Math#atan2(double, double)
[search for examples] [view on GitHub] [view on old javadoc] [view source]

## atan2

atan2( double y, double x ) → double

4-quadrant arc tangent. From the Java atan2 documentation: "Returns the angle theta from the conversion of rectangular coordinates ( x, y) to polar coordinates (r, theta). This method computes the phase theta by computing an arc tangent of y/x in the range of -pi to pi."

Note different languages have different argument order. Microsoft Office uses atan2(x,y); IDL uses atan(y,x); Matlab uses atan2(y,x); and NumPy uses arctan2(y,x).

### Parameters

y - the y position
x - the x position

### Returns:

the angle in radians

### See Also:

Math#atan2(double, double)
[search for examples] [view on GitHub] [view on old javadoc] [view source]
atan2( Object dsy, Object dsx ) → QDataSet [view source]

## autoHistogram

autoHistogram( QDataSet ds ) → QDataSet

AutoHistogram is a one-pass self-scaling histogram, useful in autoranging data. The data is fed into the routine, and bins will grow as more and more data is added, to result in about 100 bins. For example, if the initial binsize is 1.0 unit, and the data extent is 0-200, then bins are combined so that the new binsize is 2.0 units and 100 bins are used.

### Parameters

ds - rank N dataset (all ranks are supported).

### Returns:

rank 1 dataset
[search for examples] [view on GitHub] [view on old javadoc] [view source]