Amongst other things, I like to keep a detailed track of where I have been [especially during hiking in the woods, venturing into areas that I have never been before, etc.]. For this purpose, I have configured my Garmin GPSMap 60CSx to record location/date-time data every three seconds and a while ago, I described another API I wrote to store these track points in MySQL. Added advantage of this, as I have mentioned before in previous posts, is that it can be used for geotagging my photographs. For completeness sake, the MySQL table structure that holds track data is given below:
Continue reading … “PHP – Computing Total Travel Distance From GPS Tracks”
Let us consider the following (hypothetical/real) case: we have a fruit basket with an assortment of fruits in it. Over a period of time, let us suppose we accumulate so much fruit [will they not stink? may be – but that’s a problem beyond the scope of PERL & MySQL] that one basket can no longer hold all the fruits. One possible [and meaningful] way to solve this problem is to introduce another basket and segregate fruits into either one of the two baskets. To make it bit more elegant, we should probably make sure that a given kind of fruit is stored in only one of the baskets. Then, when someone asks us for a fruit – say an Apple – we know which basket contains apples and we can readily pick them out; when someone else asks for an Orange, we can repeat the process; and so on.
Though the term waypoint has come into fairly common use in recent times, the concept has existed for as long as we have been navigating. Waypoints have traditionally been associated with distinctive features of the physical world – such as mountains, rock formations, lakes, buildings, and so on. With the advancement of technology and times, waypoints have become increasingly abstract, often having no obvious relationship to any distinctive feature of the physical world. Such waypoints are used to define invisible routing paths for navigation. And for the sake of this discussion/article, we will stick to the following definition of a waypoint: a set of co-ordinates – latitude & longitude, and sometimes altitude – to uniquely identify a point in our physical universe.