Mike, If you're values are more or less 'normally' (in the statistical sense) grouped around a mean, then you could calculate the standard deviation for each list and exclude those records which fall without a distance x*SD from the mean where x is a factor (e.g. 2) which you will have to decide on. Richard Burkmar. Mike Atkinson wrote: I have a series of lists of between 25 and 150 records each with a distance field from a known point. (these are distances of properties from a linear feature centrepoint). ... I understand I need to calculate a maximum permissible value (this will be different for each grouping), my problem is how calculate this value (exclude the values of the records considered in error) before I know which records are in error!! ---------------------------------------------------------------------- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
