public static boolean isWithinPpm(double mz1, double mz2, double ppm) {
    return Math.abs(amu2ppm(mz1, mz1 - mz2)) <= ppm;
  }
public static boolean isWithinPpm ( double mz1 , double mz2 , double ppm ) { return Math . abs ( amu2ppm ( mz1 , mz1 - mz2 ) ) <= ppm ; }
Check if the 2nd m/z value is within some PPM distance from the 1st one. PPM will be calculated
based on the 1st m/z value.

@param mz1 PPM tolerance will be calculated relative to this value
@param mz2 the value to check for being within some PPM range