Hello all, I am trying to identify a known pattern of mass spectral peaks in a Labview data collection code in real time. My data collect occurs on 50 ms intervals (20 Hz). Unfortunately, my analysis routines are taking ~160 ms to complete, and therefor causes my hardware to miss data collects. Using the profile tool, it appears that one of the key offenders is a subroutine that predicts what the full spectrum should be, assuming that a few common peaks of desired spectral pattern are in the spectrum. It creates a spectrum of gaussians for the prediction, which it then compares to the real peaks. If it doesn't correlate well, then the guess is wrong; if it does correlate, then the code returns what the masses of the peaks are. I can then find the bounds of the peaks (I need the area of the peak, not just the peak location), and use them for science. In any event, it has to run the subroutine to make the predicted spectrum numerous times. Typically I am predicting the locations of 4 peaks in the spectrum, and the spectrum is commonly 3000 points long. So my routine to make a predicted spectrum has the following inputs: Where size is the # of points, width is the 1/2 width of all of the peaks, amplitude is the height of an individual peak, and center is the location of the peak in the 3000 point spectrum. Gaussian array is the output. The code looks like this: (vi attached below) My question is: Can I can do something to improve the speed of this calculation (in other words, am I doing something dumb?)? Or is this pretty much as efficient a subroutine as is possible? Many thanks for your insight! RipRock

The /500 and x500 is to map between the input number ("x") and the lookup table index - i.e. each lookup table value maps to a change in "x" of 0.002 (1/500). That could easily be any other mapping depending on how big you want your lookup table to be. By the way, the Interpolate 1D Array function has the capability of defining the lookup table using an array of clusters, where the cluster includes both the x value and its result - however this turns out to be at least a hundred times slower!

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GregS - thanks for your help! I really appreciate having a third party take a look and show me how to improve things. I also hope this peak finding example helps others who need to automatically identify peaks and ratio peak areas!

The labview forum rocks!

Thanks again,

RipRock