An object-oriented programming language

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1answer
78 views

What packages are required to install C++ API on Linux Mint 17?

What packages are required to install C++ API on Linux Mint 17? I already have access to the Python API (installed via “python-qgis” package), but no C++.
2
votes
2answers
605 views

How to convert latitude, longitude to EPSG 3857?

I'm looking to study the math involved to see how a given latitude and longitude in decimal degrees can be converted to epsg 3857. Can anybody point to a good reference or a possible python/c/c++/java ...
1
vote
1answer
120 views

Set up GDAL for C++ in RHEL

I've got GDAL installed from the latest 1.11.2 source, but when I try to make by C++ executable I get undefined references to "GDALAllRegister" and basically all the GDAL functions I call. The same ...
2
votes
1answer
115 views

Implement r.cross / ArcGIS Combine with GDAL

I am using GDAL to process a lot of rasters. I then need to combine all the arrays to create a single output raster that represents all the unique combinations of values. I.E the same thing as ...
1
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2answers
584 views

QGIS Rule Based Rendering

I am looking for an example of how to use the QgsRuleBasedRendererV2 to filter features of a layer based on an attribute value (0 or 1). Has anyone done this in Python or C++?
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0answers
121 views

GDAL, Georeferencing

I have been trying to use GDAL library to add geoinformation to an image. From the documentation from GDAL web page I could find that I could use GDAlSetGeotransform(), for that I need a six ...
2
votes
1answer
62 views

Loading Raster using QGIS API in Windows

I am trying to develop a C++ application using QGIS. I have to load a tif file and show it. First I wrote an app similar to samples on the internet. It works on Linux, but it does not work on ...
2
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0answers
150 views

Microsoft Visual C ++ Crash when Install qgis.2.8.1

I have installed and reinstall QGIS ver.2.8.1. and always display a message as shown below. I hope someone can help me fix these problems. Thanks for your help.
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0answers
43 views

QgsSpatialIndex crash my deploy C++ QGIS custom application on windows

When I use the QgsSpatialIndex class, after leaving the method, my application crash. Looks like the object QgsSpatialIndex class works, it brings QgsFeatureId list, but from what I noticed something ...
1
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1answer
208 views

Run C++ standalone application in debug mode

I write simple C++ standalone application using QGIS. It works and render vector layers from PostgeSQL database. #define CORE_EXPORT __declspec(dllimport) #define GUI_EXPORT __declspec(dllimport) ...
5
votes
2answers
2k views

GDAL in C++: Reading a ShapeFile

I am trying to use the GDAL Lib to read a ShapeFile (.shp). I followed the instructions of http://www.gdal.org/ogr_apitut.html - But it doesn't work! #include <gdal_priv.h> #include ...
1
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4answers
614 views

How to crop Geotiff image in C++ (GDAL or other possibilities)?

I am developing a code to process a geotiff image. But firsly I need to crop a geotiff image preserving its metadata (projection...) in C++. My idea it's to provide the corners and the geotiff image ...
3
votes
1answer
393 views

DEM creation with C++ application

I am implementing a C++ application that must produce DEMs from LIDAR data. I am following the next workflow: Write .las files from lidar data. Use PCL algorithms to transform/filter the point ...
1
vote
1answer
249 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
vote
1answer
139 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
votes
1answer
213 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>( ...
1
vote
1answer
149 views

Why does GDAL Polygonize flip features vertically? [closed]

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 ...
1
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0answers
91 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 ...
3
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0answers
104 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 ...
0
votes
1answer
414 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 ...
4
votes
2answers
258 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 ...
1
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0answers
22 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
47 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
votes
1answer
889 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(): ...
0
votes
1answer
262 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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0answers
26 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 ...
1
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0answers
53 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
votes
0answers
63 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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0answers
87 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
votes
1answer
389 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 ...
1
vote
1answer
44 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
58 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 ...
0
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0answers
287 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
votes
1answer
228 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. ...
3
votes
1answer
1k 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
votes
1answer
480 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 ...
2
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0answers
302 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 ...
1
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0answers
185 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 ...
1
vote
2answers
322 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
votes
2answers
742 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
votes
1answer
143 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
138 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 ...
1
vote
2answers
504 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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0answers
151 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
1k 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
29 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 ...
0
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0answers
26 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++.
0
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0answers
81 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 ...
1
vote
2answers
163 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
273 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 ...