How do I Use the Sample Compression Express VI to Reduce the Size of My Data?

Updated May 3, 2018

Reported In

Software

  • LabVIEW Professional

Issue Details

I want to compress and observe the maximum, minimum, and mean values of the data I am acquiring. Can I use the Sample Compression Express VI to do this?

Solution

You can use the Sample Compression Express VI to compress, or reduce, an input signal. A reduction factor is the number of points in the input signal that you want to reduce into one point. For example, for a reduction factor of 5, the Express VI condenses every five points to one point based on the reduction method you select: Minimum, Maximum, Last, Mean, or Median.

Given the following input signal, the table below shows the effect each of the reduction methods has on the signal.

Signal: [5, 7, 3, 2, 1, 12, 4, 5, 18, 3, 17]
Reduction Factor: 5

The number of elements in the input signal is not a multiple of the reduction factor. In this case, the Express VI uses zero padding to add zeros to the end of the signal and create a complete reduction set.

Reduction Sets: [5, 7, 3, 2, 1], [12, 4, 5, 18, 3], [17, 0, 0, 0, 0]
 
Reduction MethodOutput
Minimum[1], [3], [17]
Maximum[7], [18], [17]
Last[1], [3], [17]
Mean[3.6], [8.4], [17]
Median[3], [5], [17]

Attached is an example of how to implement the Sample Compression Express VI

 

Additional Information






Refer to the LabVIEW Help for this Express VI for more information. You can access the help for this Express VI by right-clicking it on the block diagram and selecting Help from the shortcut menu.

WAS THIS ARTICLE HELPFUL?

Not Helpful