Random selection of rows from a 2D array then subset both the rows that were selected and those that were not. Please see message below.

Question

For example, I have a 2D array with 46 rows and 400 columns. I would like to randomly select 46 data rows from the 2D array. By doing the random selection it means that not all individual 46 rows will be selected some rows may appear more than once as there may be some duplicates or triplicates in the random selection. The importan thing is that we will have randomly selected 46 rows of data (no matter that some rows appear more than once). Then I would like to subset these randomly selected 46 data rows (some which will be duplicated, or triplicated, etc.) and then also find and subset the rows that were not selected. Does this make sense? Then i would like to do this say 10 times for this data set. So that then I will have 2 by 10 data sets: the first 10 each with 46 rows and the other 10 with n rows depending on how many WERE NOT randomly selected. i hope that my explanation is clear. I am relatively new to Labview. It is really great so I am getting better! If anyone can help me with this problems it will be great. RVR

Answer 1

Start by generating randon #s between 0 and 45. Run a for loop X times and in it use the random function, multiply the result by X and round down (-infinity). You can make this into a subVI, which you can reuse later. In the same loop, or in a different one, use Index Array to extract the rows which were selected (wiring the result out of the loop with auto indexing causes it to be rebuilt into a 2D array).
One possible solution for the second part would be to go over the array of randomly generated numbers in a for loop and use Search 1D Array to find each of the numbers (i). If you get -1, it means the row wasn't selected and you can extract it.
I hope this puts you on the right path. If not, don't be afraid to ask more.
To learn more about LV, I suggest you read the LabVIEW user manual. Also, try searching this site and google for LabVIEW tutorials. Here and here are a couple you can start with. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide.
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