A script to calculate S/N ratio values
It takes four command line arguments: signal2noise ms1FileName ms2FileName percentage(20, 30 etc) intensityThreshold
where percentage for percentage of least intense peaks to be treated as noise intensityThreshold is the precursor intensity threshold set to trigger ms2, e.g, 1000, 10000, 100000. The program require the DTASelect result in the same folder as the ms1 and ms2 files
It generates two output files, percentageIntensityThresholdMs2FileName.ratio file and percentageIntensityThresholdMs2FileName.problem file. The first file contains the results and the second file contains the scans that the precursor intensity are lower than the intensity threshold. The .ratio file contains the following seven fields "ScanNumber\tIntensity\tSignal2NoiseRatio\tzScore\tmean\tsigma\tdeltaMass(ppm)"
Intensity : precursor intensity
Download it at http://fields.scripps.edu/downloads.php