Tag Info

New answers tagged

3

I'm not familiar with programming in JavaScript but in the OpenStreetMap Wiki there is a section describing "Mercator". Following this link you'll find a sample code snippet to tranform from lat long to mercator. I actually don't know if it's correct because I did not test the code.


0

Using stratified random point sampling will allow you to say "10 points in this class", eg in QGIS. You might need to convert to polygons first, I am not sure.


1

Right click your table in the "Table of Contents" click "Display XY Data." Choose whichever fields map to X, Y, and Z, then choose your coordinate system. Right click the event layer, and export to your desired location.


1

You can project latitude-longitude coordinates into any UTM zone you want. If you know that you're displaying a map in zone 35 South but there are coordinates that would normally fall within zone 36 South, just project them into 35 South instead. If your display was in some other coordinate system, "Pseudo-Mercator", EPSG::3857, and the incoming points ...


2

You can save the csv layer as shapefile to edit the data. Therefore right click the added csv layer in the layer menue and select Save as.... Following dialog will open: Now you can save your csv as shapefile. The resulting shapefile is editable.


2

Since you didn't specified which software you re using I'm assuming that is either ArcGIS or QGIS. ArcGIS: you can change the Later's coordinate system by right-clicking it on the table of contents and choosing another UTM zone, this only changes the view a not the data it self. to change the data's coordinate system use the Project tool under Data ...


0

I am not very exerienced, but I would try function geometry ST_MakePolygon(geometry outerlinestring, geometry[] interiorlinestrings);


0

I haven't heard about that problem yet but there can be basically just two things wrong. Either the projection of the shapefile is not correct or you messed up the "save as" function with any inputs apart from what is set default. i tried it with a random shp file with same version and for me it works. So check your settings.


0

The conversion code was supplied by peterv6i in this thread. http://forums.sideimagingsoft.com/index.php?topic=7785.msg48682#msg48682 public static double MMtoEllipsiodDegLatitude(double Lat_m) { if (Math.abs(Lat_m) < 15433199.0D) { if (Lat_m != 0.0D) { return Math.atan(Math.tan(Math.atan(Math.exp(Lat_m / 6378388.0D)) * 2.0D - ...


1

As pointed out by @mdsumner, You can read a SpatialGridDataFrame directly using readGDAL in the rgdal package. You can also easily coerce raster objects to a SpatialGridDataFrame or matrix. If your imagery is in separate files I would recommend reading them in as a stack and then coercing to a SpatialGridDataFrame. require(raster) require(rgdal) # Using ...


0

install raster package, then load band by band. Then you can use landsat package. Ex: library(raster) setwd(L8 folder) b1=raster("L8b1.tif") b2=raster("L8b2.tif") image=stack(b1,b2)


0

A river has more than one coordinate, so I wonder if you want a center coordinate, or the whole river geometry. You have the latter already in the shapefile. To export the geometry to coordinate points, you can use the MMQGIS plugin. If you want the center coordinate, create small buffers around the lines, and let QGIS calculate the centroid of those ...


0

The OSM wiki page is perfect : http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Lon..2Flat._to_tile_numbers_2 Here is the extracted answer (in pseudo code) for quick reference. Given Longitude/latitude/zoom to tile numbers : n = 2 ^ zoom xtile = n * ((lon_deg + 180) / 360) ytile = n * (1 - (log(tan(lat_rad) + sec(lat_rad)) / π)) / 2 Given Tile ...


3

Regarding your Post Scriptum: You already use the right projection. CRS:84 is synonymous to the EPSG-Code: 4326, which is the Coordinate-Reference-System known as: WSG84. You can always use EPSG-Codes instead of CRS-Names. EPSG-Codes are not so ambiguous in my opinion. In your Example, the transform-srs-parameter (-t_srs) would look like this: -t_srs ...


1

Just incase some had the same problem as me. The lat and long fields dont change their values when you do the correct projection. Once you are in the correct projection system in the dataframe, and you export the data using that GCS projection system, you then add the layer to the dataframe. Next, you need to go to the attributes table for that new layer. ...


3

The clue is in the name :-) You downloaded boundary lines when infact you wanted to use States and Provinces which is a polygon layer.


0

BabaCAD with new ESRI shapefile add-on is all you need (freeware). You can also filter data in attribute table view and copy selection to a new layer.



Top 50 recent answers are included