point

I'm using gnuplot to analysis data. And I frequently use palette and matrix. However whenever I use that, precision is always problem. If I increase precision by define many color, it is difficult to remember and to read. If I decrease number of color to clear comparison, precision become decrease. So I'm thinking matrix with plot number. If I can display both color and number, it will be more easy to see and analysis. At least I want display only number,(Just use excel is a one choice but I don't want to) or display number with different color.(color determined by point value) If you know the

I have a route (as a LINESTRING) and two vehicles with a position (as a POINT). I need to calculate the distance between the two points over the route. As an added difficulty I think I also need to measure the distance from the point to the closest point on the line in the case that the vehicle is not on the route at that moment. I'm using this to find the closest point on the route: SELECT ST_AsText(ST_ClosestPoint(pt,line)) AS cp_pt_line, ST_AsText(ST_ClosestPoint(line,pt)) As cp_line_pt FROM (SELECT 'POINT(100 100)'::geometry As pt, 'LINESTRING (20 80, 98 190, 110 180, 50 75 )'::geometry As

I am making a simple game and stumbled upon this problem. Assume several points in 2D space. What I want is to make points close to each other interact in some way. Let me throw a picture here for better understanding of the problem: Now, the problem isn't about computing the distance . I know how to do that. At first I had around 10 points and I could simply check every combination, but as you can already assume, this is extremely inefficient with increasing number of points. What if I had a million of points in total, but all of them would be very distant to each other? I'm trying to find a

I'm pretty sure that I'm doing multiple things wrong here but I'm not sure what... The table (minus a few fields): CREATE TABLE IF NOT EXISTS `stuff` ( `id` int(10) unsigned NOT NULL AUTO_INCREMENT, `lat` decimal(12,7) NOT NULL, `lon` decimal(12,7) NOT NULL, `location` point NOT NULL, UNIQUE KEY `id` (`id`), KEY `distance` (`distance`), KEY `lat` (`lat`), KEY `lon` (`lon`), SPATIAL KEY `location` (`location`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=5; The triggers to automatically set the location point: DROP TRIGGER IF EXISTS `stuff_insert_defaults`;

If I have a series of points as longitude and latitude, how would I calculate the center of all of those points? Geomidpoint covers 3 different methods for calculating this. Several people have answered to take the mean of the latitudes and longitudes. This is sort of the right idea, but means are more complicated on the sphere . The latitude/longitude representation is essentially artificial and has discontinuities (at the poles, and opposite the prime meridian if you aren't careful), so it taking means in it doesn't seem likely (to me) to have a sensible geometric interpretation. I think you

I'm having trouble using the pointtype command on gnuplot. I've tried several ways such as: set pt 5 set pointtype 5 plot " " w pt 5 plot " " w pointtype 5 And for some reason nothing seems to work. I tried using the "help" feature, and apparently my version of gnuplot doesn't have "pt" or "pointtype" as an option. Is this perhaps listed as some other feature. I know the points are there, when I plot multiple sets of data, the point type automatically changes, but I have no personal control over choosing the point type. Any help would be greatly appreciated. You first have to tell Gnuplot to