in place element structure

[jon_mcbee]

I am trying to figure out how to use the in place element structure to replace the nested for loops below.  Essentially I am just subtracting a constant from each index in the array, a job fit for the inplace element structure.  Apparently I dont fully understand how to use the in place element strucutre, anyone care to shed a little light for me?

Thanks!





Message Edited by jmcbee on 06-09-2008 09:53 AM

[altenbach]

You can only access single elements with the array in/out feature of the in place element structure, not entire rows or columns.

I would just do the following:

Message Edited by altenbach on 06-09-2008 09:06 AM

[jon_mcbee]

Thank you altenbach.  Would placing an inplace element structure within that for loop, to do the subtraction in place, have any benefit?

[andre.buurman@carya]

One optimisation could be to remove to inner for loop and subtract the value from the 1D array directly instead of doing them one by one.

[Joe_H]

It would depend on the size of the arrays. If the arrays are large then I would use the In place structure. If they are kind of small then just use it as it is.

[jon_mcbee]

The arrays can be pretty large, large enough to use all available memory and have labview implode.  Down the line I write this large array to file.  I am currently using the write to spreadsheet.vi, this is usually where I get the "there is no available memory" message from labview.  I am guessing that the problem lies in converting the large 2D array into a string, using the array to spreadsheet string.vi that happens within the write to spreadsheet.vi.  Any thoughts on optimizing the process of writing a large 2D array to file?

Thanks

[altenbach]

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jmcbee wrote:
Thank you altenbach.  Would placing an inplace element structure within that for loop, to do the subtraction in place, have any benefit?

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Here's the version using the in place structure. I don't think it would provide any benefit. It just complicates the code. 😉

You can check for buffer allocations, but I think my original suggestion is the way to go. LabVIEW will do it very efficiently.

 

Message Edited by altenbach on 06-09-2008 09:19 AM

[JeffOverton]

They went over this at the LabVIEW DevDay I went to.  Because the 2d arrays in altenbach's example (the beginning and end arrays) are the same size, LabVIEW will automatically do the operation in-place.