Search Results

Search found 2109 results on 85 pages for 'gis man'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 6/85 | < Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >

  • Algorithm to determine which points should be visible on a map based on zoom

    - by lgratian
    Hi! I'm making a Google Maps-like application for a course at my Uni (not something complex, it should load the map of a city for example, not the whole world). The map can have many layers, including markers (restaurants, hospitals, etc.) The problem is that when you have many points and you zoom out the map it doesn't look right. At this zoom level only some points need to be visible (and at the maximum map size, all points). The question is: how can you determine which points should be visible for a specified zoom level? Because I have implemented a PR Quadtree to speed up rendering I thought that I could define some "high-priority" markers (that are always visible, defined in the map editor) and put them in a queue. At each step a marker is removed from the queue and all it's neighbors that are at least D units away (D depends on the zoom levels) are chosen and inserted in the queue, and so on. Is there any better way than the algorithm I thought of? Thanks in advance!

    Read the article

  • Nearmap architecture

    - by portoalet
    Looking at http://www.nearmap.com/, Just wondering if you can approximate how much storage is needed to store the images? (NearMap’s monthly city PhotoMaps are captured at 3cm, 5cm, 7.5cm, or 10cm resolution) And what kind of systems/architecture is suitable to deliver those data/images? (say you are not Google, and want to implement this from scratch, what would you do? ) ie. would you store the images in Hadoop, and use memcache to deliver etc ?

    Read the article

  • ESRI frameworks: java vs javascript

    - by Luke
    I'm about to develop a web mapping application with ESRI Products like ArcGIS Server and Image Server. I can't find a good comparison between the Java Web ADF and the Javascript Framework. They're of course different because one is a full environment and the other is only client side but it's much more concise and the step to start is minimal. Another problem is that the Java Web ADF is not compatible with our current application server (JBoss 4.2.2) and require an old 4.0.2 version. Someone out there has experience that can help me? Many thanks.

    Read the article

  • Calculating bounding grid coordinates to a user click on google maps/google earth

    - by user170304
    Hello, I have a requirement to calculate the centroid or geodesic midpoint of when a user clicks in between the lat/long grid crossing. The crossing forms a square in most parts of GE and sometimes elongated rectangles. This is due to the shape of the earth of course. I'm looking for a valid mathematical formula that would allow a user to click anywhere in between this grid and then an accurate function (in Javascript or server side code) that would take an assumed grid resolution (say 1km intervals for this discussion) and the input coordinates that should return a centroid coordinate within that graticule grid. To clarify please take a look at the attached image to my google group post: http://google-earth-api.googlegroups.com/web/Picture+5.png?gda=h5oFPz8AAAD315KpovipQeBwdfGpmW3ZhBc9PTADwYa-n193hZ6AItFmHuno63c7phcEXYVuRA6ccyFKn-rNKC-d1pM%5FIdV0&gsc=sz6bbAsAAABBKF7YXWYyc4GmXg-QruHj What I need to be able to do is if a user clicks anywhere in this grid square, I need to find the centroid or center point of that grid intersection/square or at least the bounding grid coordinates (that make the square). If we assume that the grid is UTM standard and has a max resolution of 1km (or make this a parameter), I need to detect the four other points nearby and then calculating the centroid is not as difficult. I welcome any feedback you all may have and appreciate it. I don't have a simple way of letting a user click anywhere on the grid and finding the grid bounding coordinates (making a square of 4 coordinates) or the centroid / midpoint of the graticule grid square necessary. One thought is to use assumptions as much as possible using a reference such as UTM coordinate reference. If I assume that the grid is X degrees wide, can we have a pure javascript function take any input coordinate and return for me the bounding graticule coordinates in Decimal Degrees? Another thought I had was to create the grid in a geo-spatial layer to take any input coordinate and return the nearest centroid of the graticule? Does this make sense? Thanks! Omar

    Read the article

  • PostGIS - can't create spatially-enabled database

    - by itgorilla
    I'm using Ubuntu 10.10, PostgreSQL 9.0 and PostGIS 1.5. I've installed PostGIS 1.5 from: https://launchpad.net/~ubuntugis/+archive/ubuntugis-unstable I used PPA first then the command: sudo apt-get install postgis to install postgis. I've been following these instructions to create a spatially-enabled database: http://ostgis.refractions.net/docs/ch02.html#id2630100 I got to the point where it's saying: Now load the PostGIS object and function definitions into your database by loading the postgis.sql definitions file (located in [prefix]/share/contrib as specified during the configuration step). psql -d [yourdatabase] -f postgis.sql Well, there is no postgis.sql on my server after the installation. I did an sudo updatedb to make sure I can find postgis.sql but it's not there. Any ideas? Thank you!

    Read the article

  • What is the difference between Multiple R-squared and Adjusted R-squared in a single-variate least s

    - by fmark
    Could someone explain to the statistically naive what the difference between Multiple R-squared and Adjusted R-squared is? I am doing a single-variate regression analysis as follows: v.lm <- lm(epm ~ n_days, data=v) print(summary(v.lm)) Results: Call: lm(formula = epm ~ n_days, data = v) Residuals: Min 1Q Median 3Q Max -693.59 -325.79 53.34 302.46 964.95 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 2550.39 92.15 27.677 <2e-16 *** n_days -13.12 5.39 -2.433 0.0216 * --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 410.1 on 28 degrees of freedom Multiple R-squared: 0.1746, Adjusted R-squared: 0.1451 F-statistic: 5.921 on 1 and 28 DF, p-value: 0.0216 Apologies for the newbiness of this question.

    Read the article

  • Mapping Application for Middle East

    - by Faraz
    We have a desktop application that has been using MapPoint for displaying data on a European map. We now want to support Middle East maps, but MapPoint only support North America and Europe. Is there any other alternative to MapPoint that can be easily integrated in a .NET based Win Forms application?

    Read the article

  • How to find relation between change in latitudes at centre of map and top/bottom

    - by Imran
    Hi, Im having little trouble finding a relation between the movement at centre and edge of a circle, Im doing for panning world map,my map extent is 180,89:-180,-89, my map pans by adding change(dx,dY) to its extents and not its centre. Now a situation has arrrised where I have to move the map to a specific centre, to calculate the change in longitudes is very easy and simple, but its the change in lattitudes that has caused problem. It seems the change in centreY of map is more than the change at edge of the mapY, or simply if I have to move the map centre from 0long,0lat to 73long,33lat, for dX I simply get 73, but for dY apparently it looks 33 but if i add 33 to top of map that is 89 , it will be 122 which is incorrect since Latitudes are between 90 and -90 . It seems a case a projection of a circle on 2D plane where the edge of circle since is moving backward due to angle expereinces less change and the centre expereinces more change, now is there a relation between these two factors? I tried converting the difference between OriginY and destinationY into radians and then add to Top and Bottom of Map, but it did'nt really work for me. Please note that the map is project on a virtual canvas whose width starts from 256 and increases by 256*2^z , z=0 is default and whole world is visible at that extent of canvas code: public void moveMapTo(double destinationLongitude,double destinationLattitude) // moves map to the new centre { double dXLong=destinationLongitude-centreLongitude; double atanhsinO = atanh(Math.sin(destinationLattitude * Math.PI / 180.00)); double atanhsinD = atanh(Math.sin(centreLatitude * Math.PI / 180.00)); double atanhCentre = (atanhsinD + atanhsinO) / 2; double latitudeSpan =destinationLattitude - centreLatitude; double radianOfCentreLatitude = Math.atan(Math.sinh(atanhCentre)); double dXLat=latitudeSpan / Math.cos(radianOfCentreLatitude); dXLat*=getLattitudeSpan()*(Math.PI/180); <--- HERE IS THE PORBLEM System.out.println("dxLong:"+dXLong+"_dxLat:"+dXLat); mapLeft+=dXLong; mapRight+=dXLong; mapTop+=dXLat; mapBottom+=dXLat; } ////latitude span function private double getLattitudeSpan() { double latitudeSpan = mapTop - mapBottom; latitudeSpan = latitudeSpan / Math.cos(radianOfCentreLatitude); return Math.abs(latitudeSpan); } //ht

    Read the article

  • Need a list of all countries in the world, with a longitude and latitude coordinate

    - by ptrn
    I need a list of all the countries in the world, with one lat/long coordinate for the country. I had a look at GeoNames, but all I can seem to find are lists that have the countries as well as cities in the same list. I guess I can just parse it and filter out the countries, but I was hoping to avoid that. Basically, what I need; Country name - Lat/long coordinate (some sort of center of the country) It doesn't need to say anything about continent, but I wouldn't mind if it did. _L

    Read the article

  • Designing a WPF map control.

    - by Dylan
    I'm thinking about making a simple map control in WPF, and am thinking about the design of the basic map interface and am wondering if anyone has some good advice for this. What I'm thinking of is using a ScrollViewer (sans scroll bars) as my "view port" and then stacking everything up on top of a canvas. From Z-Index=0 up, I'm thinking: Base canvas for lat/long calculations, control positioning, Z-Index stacking. Multiple Grid elements to represent the maps at different zoom levels. Using a grid to make tiling easier. Map objects with positional data. Map controls (zoom slider, overview, etc). Scroll viewer with mouse move events for panning and zooming. Any comments suggestions on how I should be building this?

    Read the article

  • Get street address at lat/long pair

    - by Chris Wenham
    I've seen that it's possible to get the latitude and longitude (geocoding, like in Google Maps API) from a street address, but is it possible to do the reverse and get the street address when you know what the lat/long already is? The application would be an iPhone app (and why the app already knows lat/long), so anything from a web service to an iPhone API would work.

    Read the article

  • General Address Parser for Freeform Text

    - by Daemonic
    We have a program that displays map data (think Google Maps, but with much more interactivity and custom layers for our clients). We allow navigation via a set of combo boxes that prefill certain fields with a bunch of data (ie: Country: Canada, the Province field is filled in. Select Ontario, and a list of Counties/Regions is filled in. Select a county/region, and a city is filled in, etc...). While this guarantees accurate addresses, it's a pain for the users if they don't know where a street address or a city are located (ie, which county/region is kitchener in?). So we are looking at trying to do an address parser with a freeform text field. The user could enter something like this (similar to Google Maps, Bing Maps, etc...): 22 Main St, Kitchener, On And we could compartmentalize it into sections and do lookups on the data and get to the point they are looking for (or suggest alternatives). The problem with this is that how do we properly compartmentalize information? How do we break up the sections and find possible matches? I'm guessing we wouldn't be guaranteed that the user would enter data in a format we always expected (obviously). A follow up to this would be how to present the data if we don't find an exact match (or find multiple exact matches... two cities with the same street name in different counties, for example). We have a ton of data available in the mapping data (mapinfo tab format mostly). So we can do quick scans of street names, cities, states, etc. But I'm not sure about the best way to go about approaching this problem. Sure, using Google Maps would be nice, bue most of our clients are in closed in networks where outside access is not usually allowed and most aren't willing to rely on google maps (since it doesn't contain as much information as they need, such as custom map layers). They could, obviously, go to google and get the proper location then move to our software, but this would time consuming and speed of the process can be quite important.

    Read the article

  • Split or save a subset of a ESRI Shape SHP file to a new file?

    - by Eric Palakovich Carr
    I'm working with shape files in GeoDjango. Right now I'm trying to write a test for code that loads in a shape file and saves it to a database. The shape file currently has a feature count of 64,118. I'd like to reduce this to a handful so the test can quickly load it and confirm everything is right. Since shape files aren't in a text format, is there a free application or library I can use to pluck out a handful of features and save them to a new file? I should mention I don't have a license nor access to any of the ESRI product line.

    Read the article

  • Finding Cities within 'X' Kilometers (or Miles)

    - by Mike Curry
    This may or may not be clear, leave me a comment if I am off base, or you need more information. Perhaps there is a solution out there already for what I want in PHP. I am looking for a function that will add or subtract a distance from a longitude OR latitude value. Reason: I have a database with all Latitudes and Longitudes in it and want to form a query to extract all cities within X kilometers (or miles). My query would look something like this... Select * From Cities Where (Longitude > X1 and Longitude < X2) And (Latitude > Y1 and Latitude < Y2) Where X1 = Longitude - (distance) Where X2 = Longitude + (distance) Where Y1 = Latitude - (distance) Where Y2 = Latitude + (distance) I am working in PHP, with a MySql Database. Open to any suggestions also! :)

    Read the article

  • Why does UMN-Mapserver shows an ERDAS Image-File (.img) as white shape?

    - by Mnementh
    I want to render an ERDAS-Image-file (suffix .img) with the UMN-Mapserver. The data is rendered on the right position and with the correct shape, but all data is white instead of an raster-image. The Image contains many layers. My mapfile looks like this: MAP NAME "Test" WEB METADATA "wms_title" "test" "WMS_SRS" "epsg:31466 epsg:31467 epsg:31468 epsg:31469 epsg:4326 epsg:25832 epsg:3035" END LOG "test.log" IMAGEPATH "." END SHAPEPATH "." PROJECTION "init=epsg:32632" END LAYER NAME "testlayer" TYPE RASTER DATA "test.img" STATUS ON OFFSITE 0 0 0 END OUTPUTFORMAT NAME png DRIVER "GD/PNG" MIMETYPE "image/png" IMAGEMODE RGBA END END

    Read the article

  • Moving a Point along a Path in SQL Server 2008

    - by David Pfeffer
    I have a geography field stored in my database, holding a linestring path. I want to move a point n meters along this linestring, and return the destination. For example, I want the destination point 500 meters along the linestring starting from its beginning. Here's an example -- what is the YourFunctionHere? Or, is there another way? DECLARE @g geography; SET @g = geography::STGeomFromText('LINESTRING(-122.360 47.656, -122.343 47.656, -122.310 47.690)', 4326); SELECT @g.YourFunctionHere(100).ToString();

    Read the article

  • Find point which sum of distances to set of other points is minimal

    - by Pawel Markowski
    I have one set (X) of points (not very big let's say 1-20 points) and the second (Y), much larger set of points. I need to choose some point from Y which sum of distances to all points from X is minimal. I came up with an idea that I would treat X as a vertices of a polygon and find centroid of this polygon, and then I will choose a point from Y nearest to the centroid. But I'm not sure whether centroid minimizes sum of its distances to the vertices of polygon, so I'm not sure whether this is a good way? Is there any algorithm for solving this problem? Points are defined by geographical coordinates.

    Read the article

  • How to create a HTML world map with GeoDjango ?

    - by pierre-guillaume-degans
    The GeoDjango tutorial explains how to insert world borders into a spatial database. I would like to create a world Map in HTML with these data, with both map and area tags. Something like that. I just don't know how to retrieve the coordinates for each country (required for the area's coords attribute). from world.models import WorldBorders for country in WorldBorders.objects.all(): print u'<area shape="poly" title="%s" alt="%s" coords="%s" />' % (v.name, v.name, "???") Thanks !

    Read the article

  • SQL Server 2008 spatial index and CPU utilization with MapGuide Open Source 2.1

    - by Antonio de la Peña
    I have a SQL Server table with hundreds of thousands of geometry type parcels. I have made indexes on them trying different combinations of density and objects per cell settings. So far I'm settiling for LOW, LOW, MEDIUM, MEDIUM and 16 objects per cell and I made a SP that sets the bounding box according to the extents of the entities in the table. There is an incredible performance boost from queries taking almost minutes without index to less than seconds, it gets faster when the zoom is closer thus less objects are displayed. Yet the CPU utilization gets to 100% when querying for features, even when the queries themselves are fast. I'm worrying this will not fly in a production environment. I am using MapGuide Open Source 2.1 for this project, but I am positive the CPU load is caused by SQL Server. I wonder if my indexes are set properly. I haven't found any clear documentation on how to properly set them up. Every article I've read basically says "it depends..." but nothing specific. Do you have any recommendations for me, including books, articles? Thank you.

    Read the article

  • Geocoding service for a startup?

    - by Sologoub
    I'm working on an idea for a service that uses geocoded data (lat/lng) form a US address. Google maps API v3 has been awesome, until I read the terms of service and acceptable uses a little closer. The problem is that the terms seem to prohibit use of the maps API for any commercial use where the site is not freely accessibly to the public, such as a subscription based service. The alternative offered is Google Maps API Premier, but at $10,000 per year minimum, it's just not possible at this time. Same goes for services offered by Yahoo! and MS - initial fees are small for enterprises, but for a very early stage startup (not even a finished prototype yet!) it's just not doable. Geocoding process needs to be real-time and volume would be very small - user would enter address at setup time and only update it if needed. Any help is greatly appreciated!

    Read the article

  • Displaying fancy routes in cloudmade based service

    - by Rob
    I look for a way to display a route in a fancy way using the Cloudmade service. Currently, I can see computed routes like on this tutorial http://developers.cloudmade.com/projects/web-maps-lite/examples/routing, but I look for a fancier way to do it -- without A and B tags, and with colors, etc. Is this possible ? Thanks for your help Rob

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 2 3 4 5 6 7 8 9 10 11 12 13  | Next Page >