An object-oriented programming language

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214 views

How to get values to create world file format?

i have researched regarding making world file format and tried to create one using c++ in windows, can somebody confirm if where i am getting the values from are correct? the literature regarding ...
1
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1answer
110 views

Georeferencing las files using liblas

I am trying to write georeferencing information to a '.las' file using liblas and c++. Here is my code: ofstream ofs; ofs.open("test.las", ios::out | ios::binary); liblas::Header header; ...
2
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1answer
163 views

How to make rectangle selection on QgsMapCanvas?

I have this code for create and open raster map: if(QFile::exists(rasterFileName)) { QFileInfo myRasterFileInfo(rasterFileName); m_pRasterLayer = QSharedPointer<QgsRasterLayer>( ...
2
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1answer
116 views

Why does GDAL Polygonize flip features vertically?

I am trying to convert a 1 band jpg raster into polygons. It is converting the data and I get a polygon shape file. However, the output data is vertically flipped. Input data have no reference ...
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0answers
84 views

How do I step into the C++ functions from an external Python app I'm debugging?

I just wanted to see how to step into the C++ class QgsVectorLayer()'s methods from the python call to QgsVectorLayer(self.uri.uri(),'foo','postgres'). I'm trying to debug and it trying to step into ...
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90 views

GDALRasterizeGeometries doesn't burn correct Values

What I have is a vector shape file with a string field. What I've done is written a CSV file with the field ID, field_value and now I would like to rasterize the vector layer as a byte raster with the ...
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1answer
346 views

Distance between a Point and Linestring: PostGIS/GEOS vs. Boost

I am currently using the GEOS library through OGR and data from a PostGIS database to work with geospatial data. I now found myself in the need to use some of the algorithms Boost.Geometry and ...
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2answers
238 views

Is there a GIS-Tool that fit my needs? [closed]

I´m working on a GIS-Project in the Defense & Intelligence sector. The goal was to develop/create a GIS-Service that: stores and manage GIS-Data (Map data, Height data.. ) has a repository for ...
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20 views

Getting incorrect results for Geary's Coefficient algorithm (incorrect math?)

I'm not sure if anyone here can help me with this, but I'm currently working on a program that uses a spatial autocorrelation algorithm to analyze patterns in an image. It's supposed to return values ...
2
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0answers
45 views

In version 2.4 vector layers with labeling switch off caching

I am developing a map display stand alone application using the C++ API. With version 2.6 the caching mechanism is ignored for vector layers with labels. The reason is to avoid conflicting labels. ...
2
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1answer
725 views

How to develop c++ standalone QGIS C++ Application

I want to integrate QGIS in QT\C++ application. I try to write basic C++ apllication to render map and build it using MSVC 2010. class PostGisViewer: public QMainWindow { public: PostGisViewer(): ...
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1answer
203 views

Generate delaunay triangulation from 3D(x,y,z) points

I have 3D Points array.each 3D point have x,y,z data. I want to generate delaunay triangulation.I am new in delaunay triangulation. My array as below. -256.24 85.35 5.0 -262.24 84.35 15.0 -263.24 ...
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23 views

Point Symbolizer() in rundemo.cpp file Giving error

The code is given Below: roads2_rule_11.append(point_symbolizer("abc.png")); The error is given below: rundemo.cpp: In function âint main(int, char**)â: rundemo.cpp:142:57: error: no matching ...
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0answers
52 views

when make a cross-platform c++ GIS core, how to make the 2d-drawing platform independent? [closed]

i try to develop a c++ no-GUI GIS core(i want the core have no GUI related things, do not use any GUI library) and I can figure out how to do other things except the drawing part. when cope with 2D ...
2
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0answers
61 views

What is the issue with geopdf format?

I'd like to add the geopdf format as output of a library that I am working on. After have looking around, I have not been able to find a (c, c++, python) library that meet my license requirements ...
0
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75 views

Syntax Error in qgsapplication file

I am trying to test an QGIS application code example. However, when I try to compile it, it is reporting errors in qgsapplication.h which is coming with the source code of QGIS. I am using QTCreator ...
2
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1answer
335 views

How to load a *.qgs file in a C++ QGIS standalone app?

I'm using QGIS-2.4.0 API to develop a standalone app by C++. I saved a test.qgs file in QGIS Desktop software, in the project, there was one layer and it was visible. Then I loaded the test.qgs ...
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1answer
35 views

What is a purpose of parameter 'separater' in mapnik csv plugin datasource?

What is the purpose of the parameter 'separater' in the Mapnik CSV plugin DataSource Example of the code: parameters p; p["type"]="csv"; p["inline"]=quotedStr; ...
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0answers
47 views

What is a Format of csv plugin datasource string in mapnik

I have tried that Format Is that is a correct format to pass to CSV plugin,the sample C++ code is given Below: std::string csv_string("wkt,Name POLYGON((5.123456 51.6, 6.8 52.6, 7.8 51.6, 5.123456 ...
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0answers
240 views

Open a *.qgs project file in API, why maps do not show?

I'm using QGIS-2.4.0 API. I saved a test.qgs file in QGIS Desktop, in this project, there is one layer that is visible in it. Then I open the test.qgs project file in QGIS API to developing an App, ...
2
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1answer
208 views

How to write a custom canvas item for SVG marker by subclassing QgsMapCanvasItem in QGIS?

I want to subclass QgsMapCanvasItem for SVG marker in QGIS, I looked up a similar topic in stackexchange and QGIS mailing list, I found that this is similar to mine, I did exactly what @Nathan W did. ...
2
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1answer
971 views

Looking for QGIS 2.4 C++ Hello World example?

In the project I'm working on (C/C++/Qt application), we are trying to integrate QGIS (latest version desirable, 2.4 for the moment). But there is very little information in the web on how to use QGIS ...
2
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1answer
397 views

Add band to GDAL VRT dataset and convert to TIFF

I'm trying to add a band to a TIFF dataset by converting it to a VRT format and using the AddBand() function, then convert it back to a TIFF to access the band and write the data. Here is an example ...
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0answers
257 views

How to develop a real-time navigation App using QGIS API?

I want to develop a navigation application based on QGIS using C++, for live tracking. I think it is quite normal for GIS to do such things, especially QGIS as it is a very mature GIS platform. But ...
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155 views

How to create a svg item onto Map Canvas in QGIS API?

I'm working on a project with QGIS-2.4.0 API using C++. I need to load some svg files to the application for displaying as symbols. QGIS API has a class named QgsMapCanvasItem, which is an abstract ...
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2answers
264 views

GDAL Application crashes when loading GDAL drivers

I'm developing on QT an application that uses GDAL library (which I compiled using MinGW 4.8). When I use the application on my windows 8 laptop, it works fine, but when I tried using it on several ...
2
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2answers
640 views

Error getting ESRI Shapefile driver OGR in C++

I am unable to create an OGR Layer using the C++ API. I have followed the documentation at this link exactly http://www.gdal.org/ogr_apitut.html I get an error trying to get the shapefile driver. Any ...
0
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1answer
121 views

going from hillshade to percent shaded (gdaldem)

I assumed hillshades output percent shaded (scaled to 255) at the given azimuth and altitude but this is incorrect. A flat raster at 80 degrees altitude has a maximum value of 251 instead of 255. How ...
2
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0answers
115 views

How do you clip a gnomonic or stereographic azimuthal projection?

I have polygons comprised of lat/lon coordinates and I want to project them onto a plane that's appropriate for polygon operations (such as checking for intersections). In some cases, the polygons ...
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2answers
430 views

Does QGIS support dynamic display?

I'm a new developer of QGIS using C++. I am working on a project which needs to display dynamic maps/layers(just like GPS, but it is not GPS, however it should display data alike GPS data - dynamic ...
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120 views

Rendering a geotiff block with gdal and gdk-pixbuf - Some flaws in the result

I currently try to render a geotiff file with GTKmm\GDKmm (gdk-pixbuf). The file is a tiled geotiff with a block size of 256*256 and three rasterbands. The shortened gdalinfo output is: Driver: ...
2
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0answers
852 views

Correct way to extract pixel data using GDAL. Current method gives repeated but changing value.

I am trying to open a spectral file and move bands of data from GDAL to OpenCV's Mat data structures. As of now I am just trying to make sure that I can correctly access each band using GDAL and pull ...
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0answers
27 views

change symbology of an graduated renderer in qgis

In my plugin(c++) I add a vectorlayer to map, then I change the symbology of the QgsGraduatedSymbolRendererV2 of this layer. After this I refresh the map with ...
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25 views

Write to FGDB in C++ code?

Anyone know the correct syntax for this? I'm a C++ beginner but experienced in GIS.. I'm guessing ofstream won't do it and am not sure what else to try. Never written to any sort of database in C++.
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74 views

compile QGIS-plugin for Windows: problem with gdal_i.lib version

While compiling my plugin for QGIS 2.2 there are no errors, but it ist still not loading in QGIS because of an dll error. (function not found) I think the problem is at the gdal version. The ...
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2answers
147 views

Projection for polygon intersection confined into one hemisphere?

I have polygons where each vertex is a (lon,lat) geographic coordinate. I want to find out if they intersect or contain each other. The polygons are guaranteed to never exceed a hemisphere (so they'll ...
1
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1answer
222 views

Calculate tree cover over certain area from raster data

Last year Hansen et al. published Global Forest Change map as set of raster data available in TIFF format. Basically those are 30-meters resolution satellite images with pixel values ranging from 0 ...
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229 views

gdal read whole geotif band into vector

i have another c++ GDAL question. I try to read alle elevation data out of an GeoTiff file into a c++ vector so that i can get elevation at x,y like this: vector[x][y]. I also like to use this data to ...
0
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1answer
205 views

gdal_contour transparent contour as png

I started using the GDAL Library in a c++ project. It is a great library, but I am a bit stuck right now with different aspects of it. What is the best way to use gdal_contour in my c++ programm? ...
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44 views

C++ parser for OGC Filter Encoding 1.0

I'm developing a C++ application and I have to parse a OGC Filter in order to implement querying functionality on a metadata repository. Does anyone know any C++ library to parse OGC Filters? Thanks. ...
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94 views

How to rasterize a vector data with style

I want to make a utility in c++ which can rasterize vector data with some specified style. I know about gdal_rasterize. But the problem with it is, we cannot specify the style details. Do we have a ...
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0answers
147 views

GDAL C/C++ API and filtered pyramid tile generation

I have been tasked with adding functionality to an existing C++ developed toolset whereby a source dataset (typically a single GeoTIFF) needs to be split into tiles at various resolutions ('zoom' ...
3
votes
2answers
336 views

Fastest Way to Intersect Envelope with Multiple Feature Classes ArcObjects

I have the situation where I am doing a large number of intersections and I need to do them fast. The situation is I have a iMap with 1 or more layers and a series of envelopes, lots of envelopes. I ...
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88 views

ArcObjects: How to remove a custom layer?

How is a custom layer supposed to be destructed? I have a custom layer that implements drawing by overriding IActiveViewEvents::AfterDraw. The problem is that sometimes when the custom layer is ...
2
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1answer
490 views

Rearranging labels in screen to avoid overlapping

I have a map, with some icon over it. Every icon has a label next to it. When icons overlaps, labels are overlapped too. In this case, I want to move labels so they don't overlap anymore, with a line ...
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1answer
379 views

QGIS 2.0 Howto copy raster data from a QgsRasterDataProvider to an OpenCV matrix

I'm hacking the half day arround a problem and that I' thought it was simple one. I'm using C++ (QtCreator) QGIS 2.0 und openCV2 on an 64 bit Workstation runnig Debian Wheezy. The Application I try to ...
3
votes
1answer
2k views

Is it possible to query via bounding box in the Google Maps Static API?

We have a Qt program written in C++ to request wms tiles and display them. This works fine. Now we want to display imaginery from Google Maps and due to some restrictions in our program, we can't use ...
3
votes
1answer
200 views

How to refresh layers independently?

I'm writing a C++ application using QGIS API and I would like to improve the performance. I want to render 5 layers: one raster layer using gdal to load Bing/Google Map tiles 4 custom QgsMapLayer ...
1
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1answer
114 views

how to transfer from traditional GIS software developing to internet area

I am a GIS developer, formerly doing some secondary development with GIS software. I now want to obtain some internet-based GIS area in my career. Somebody advised me to first read some ...
4
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2answers
1k views

combine raster with another raster mask file - gdal

I have 2 rasters in GeoTiff format. One has all of the land and water and the other is a mask file that shows either 0 for water or 1 for land. I basically want my output to just have the land values ...