algorithm - How to intelligently degrade or smooth GIS data (simplifying polygons)? -

-

I have a wide American county map from a dataset. I represent strikers, more boxes, less "noise to represent geographic features. "How can I get figures, how can I sample, smooth or degrade data - in this case only county boundaries and state lines, but maybe even in the general case?

Sampling time may be provided if it can be done efficiently, or a parallel data set can be generated and stored. I am using, and lines are multi-polylines generated by shp2pgsql - but any solution where you take a squaggli line and reduce it to the smooth line of almost equal importance of human interpreter Very useful.

The problem of simply throwing points is that you can distort the shape of the original polygon. One better way is to get it from the other direction; Start with the original approximation of the polygon and then refine it towards its complex shape upwards.

An excellent example of this approach is that you start with two sides drawn from a complete polygon. Add one-third peak by selecting the one located at the farthest from the edge drawn between the first two corners. Proceed by adding points, unless you have something that is equal to your original polygon.


Comments

Post a Comment

Popular posts from this blog

c# - How to capture HTTP packet with SharpPcap -

-
I would like to capture all incoming HTTP packets on my machine. To do this, I am using SharpPcap which is a WinPcap The cover is. SharpPcap works very well, but it captures TCP packets and what it wants to do for me is a very low level. Does anyone know how can I easily get full HTTP requests / reactions from all these TCP packets? Thanks SharpPcap is already able to capture the packet in the same way That's what the virus does (just in the code instead of the GUI). And you can either either parse them directly or you can put them in the drive in the common .pcap file format. The steps to parse the capture are: Open a connection at any time Loop a while Or start capturing using an event callback Parsing the raw packet for the type you want If you are reading .PPP dump files In addition to calling you an offline capture reader is almost the same, there is no need to select an interface, and you can set the majority There is no need to do the modes. All st...
Read more

php - Multiple Select with Explode: only returns the word "Array" -

-
By using Wordpress I have created a multiple selection box so that users can select categories to exclude. When the page is initially loaded, I see my predefined default option. However, when I select a new value and I save ... I only see the word "Array" and have not chosen anything else? & lt; Class = "amultiple" id = "& lt; php echo $ value ['id'] ;? gt;" name = "& gt; php echo $ value ['id'] ;; gt; []" Multiple = "multiple" size = "8" & gt; & Lt ;? Php global option; Foreign currency ($ value as value $) {if (get_settings ($ value ['id']) === FALSE {$$ value ['id'] = $ value ['std']; } And {$$ value ['id'] = get_settings ($ value ['id']); }} $ Ranges = & amp; Amp; Categories ('type = post & orderbiz = name & amp; hide_empty = 1'); If ($ ranges) {$ ex_cat = implode (',', $ tt_cat_exclude); Forex Currency ($ range a...
Read more

php - jQuery AJAX Post not working -

-
I do not understand why this script does not work. It has something to do within AJAX PostScript / Function. Right now, when I submit my form, it runs php code on the same page. What it should do, send the values ​​of the form for Project_Azax.fp, then there will be a refund of success on the page which is correct or false. $ (document) .ready (function () {$ ('div # didIt'). Hide (); $ ('form [name = adminForm]'). Submit (function () ($ {'.post' ('/ project_ajax.php', {action: $ ('[name = action]') Val (), pId: $ ('[name = pId]'). Val (), name ('[Name = name]'. Val (), url: $ ('[url = url]'). Val (), summary: ('[summary = summary]'). Val ()}, Function (data) {if (data.success) {$ ('div # didIt') .Sliddown ('slow');} and {warning ('unsuccessful SA!');}}, 'Jason'); return false ;});}); What is the code for project_ajax.php below ... if ($ _ POST ['action'] == ...
Read more