Using Extract on Multidimensional Waves

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Mon, 10/12/2020 - 08:37 am

Hi,

Is there a format to extract waves from a multidimensional wave?

Use case: I have a 2D wave with conditions (temperature, voltage) and data (resistivity, weight), and I would like to a single column of data, resistivity for example, where voltage= a fixed value and include all temperatures.  I understand the returned wave is always single dimensional, but it is vague on the source wave and how the logical expression should be constructed if it includes a multidimensional wave.

Or should I just code the breaking apart of the multidimensional wave?

Andy
Duplicate/RMD=[therow, therow] TwoDWave, waveFromRow

That will create a 2D wave with one row. If you need a 1D wave, you can add this:

Redimension/N=(numcolumns) waveFromRow

 

October 12, 2020 at 10:32 am - Permalink

Hi John,

The reason for using extract is the conditions of interest appear many times not just once.  I may be pushing IP too far, but think of  dataframe where some columns are used for the data and others for the independent variables AND there are repeated sets of conditions.  I would like to gather all the data points that meet a set of criteria and extract does this beautifully for one dimensional waves.  Can it be extended to handle multi-dimensional ones?

Andy

 

October 12, 2020 at 11:20 am - Permalink

Andy,

Use MatrixOP to express all the conditions in a single line.  Set the rows that you are not interested to NaN and then use WaveTransform with zapNaNs.  If you have access to IP9 you can do it all in MatrixOP.

 

AG

October 12, 2020 at 11:54 am - Permalink