I need to select points that have attributes that are within a relative number range of each other. For instance; given the following numbers: 95,705,139,65,537,266,525 and 188; I need to find all of those numbers that are within a range of 50, 100 and 150 of each other. I then need to find those that are within a distance of each other. I am using QGIS. Any ideas gratfully accepted. Thanks.