by Mats.E (Posted Thu Jun 19, 2008 4:42 pm)

Hi!

I need help on how to define a local cartesian coordinate system in QGIS.

I intend to use QGIS as a simple to learn tool for screen digitizing some vector data off images of essentially flat surfaces.
The images needs to be georeferenced in a local xy system for subsequent transformation into another 3D environment.

If anyone is familiar with MapInfo, I want to create the equivalent of a MapInfo non-earth tab-file in QGIS.
The resolution I need is millimeter (0.001 meter).

I have tried in vain to find the syntax rules for the proj string I guess I need to write.
Thankful for any help or links to the information I need.

Cheers, Mats.E


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by Mats.E (Posted Thu Jun 19, 2008 3:02 pm)

Hi!

I am new to QGis but know MapInfo very well. I would like to comment on the previous post.
In a separate post I will ask a related question.
Gede2A wrote:don't worry, do a new project and directly load them. I don't know why map info often says non earth proj
In MapInfo, a non-earth coordinate system is used when the tool needs to be used for non-earth related, or by definition flat data, such as data from paper drawings and such. So it is fair to assume that non-earth tables are unprojected and it would be wrong to apply an arbitrary coordinate system to them.
Unless of course you know for a fact that the data are in a known projection.
In MapInfo, you cannot show a non-earth table in a projected mapper window, or save the table in an an earth-related projection.

Regards, Mats.E


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by S.Ramesh (Posted Thu Jun 19, 2008 10:57 am)

i am working the quantum gis its problem the not save the mapping digitize ??? the write the text is not available??? delete the line is not ??? the line is trim is not available ???


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by S.Ramesh (Posted Thu Jun 19, 2008 10:53 am)

i am working the quantum gis its problem the not save the mapping digitize ??? the write the text is not available??? delete the line is not ??? the line is trim is not available ???


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by LOGU (Posted Thu Jun 19, 2008 9:24 am)

HI:
I working quantum gis small problam in q gis how type text & layer triming don't save file grate circle it's my problam


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by oxman (Posted Thu Jun 19, 2008 7:26 am)

Hello,
I am a beginner. I have been using FOSS since 1998 but I am new to GIS and its software. As a member of the local watershed council in Oregon, USA I have been appointed to try and switch our current windows based system to FOSS. Any tutorials, URLs or guidance would be appreciated.
We are using Timbril and Arcgis software currently. We have an extensive fish barrier database that I need to switch over and build upon. Is there a way to use Timbril hardware and FOSS? Any help is greatly appreciated.

Stan


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by albert lenin (Posted Thu Jun 19, 2008 7:16 am)

Need details related to digitizing maps.how to trim the lines drawn,delete,break and how to deselect the drawn lines???
the main problems is we are not able to save the work done with the map????


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by Jorre (Posted Wed Jun 18, 2008 10:29 pm)

[Damn, why did my first try at this post end somewhere in the digital nirvana?]

Seems like those modules you mentioned change the raster resolution according to the actual region settings, thus it seems necessary to first re-set the region resolution through the g.region module.
This makes sense according to my newly read (German) literature and my experiences with QGIS/GRASS so far...


Now, as QGis offers simplified versions of the modules dialog boxes (only the required parameters are shown) some options, like setting a new resolution for the region, are not accessible through QGis.
Seems like the only way to happily set the desired resolution is by dealing directly with GRASS without QGis gentle manners.
The uppermost of the GRASS modules in QGIS permits access to the GRASS shell, did you try this? You should get the full functionality via the shell, I guess. (Again I'm not very helpful - I just played around a bit with it, but yet not very successfull.) It's not that comfortable, but it should at least work without a standalone GRASS...


All the best, Jorre


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by Coy (Posted Wed Jun 18, 2008 9:59 pm)

Thank you very much Jorre, I´ve already tried each of those modules with no good results.
Just in case you would ever find your self in such situation I comment what I have have in mind nowadays: Seems like those modules you mentioned change the raster resolution according to the actual region settings, thus it seems necessary to first re-set the region resolution through the g.region module. Now, as QGis offers simplified versions of the modules dialog boxes (only the required parameters are shown) some options, like setting a new resolution for the region, are not accessible through QGis.
Seems like the only way to happily set the desired resolution is by dealing directly with GRASS without QGis gentle manners.

Best wishes and thanks!
Coy


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by sab (Posted Wed Jun 18, 2008 5:43 pm)

I was wondering whether there is a tool/plugin for QGIS to extract z values from a raster for a bunch of points (vector) and allocate that in a new attribute in point database. Something like Point Inspection in Vertical Mapper under Mapinfo.

Many thanks
Sab


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by pitta1981 (Posted Wed Jun 18, 2008 10:29 am)

hello

I have qgis 0.10 on ubuntu 8.04 with grass 6.2.2 and i have some trouble with this qgis version.

I can't load grass vector because when i try it my qgis close after a while.

When i try to load a raster from grass the output is far from the GRASS output and look like snowfall change with the visualization scale.

I have also problem with projection because when load a shapefile the projection was wrong.

thanks
Simone


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by garynobles (Posted Wed Jun 18, 2008 10:28 am)

I am trying to print a map with an associated legend how do I do this in Qgis?

I am a recent convert from ArcGIS to GRASS GIS and Qgis is excelent


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by napierite (Posted Wed Jun 18, 2008 5:16 am)

Greetings all

I have aerial TIFF images with TFW files that have rotation parameters. I have got them displayed in V0.10 OK. They come through as a black rectangle with the rotated image painted inside the rectangle. I have specified a transparent pixel value to get rid of the black surround. All good.

Now, how can I apply that setting to 100's of images at once, to get a full coverage. It will be a tedious process having to apply the same setting to each image at a time. The images are quickviews so not big files.

TIA

Nigel


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by Jorre (Posted Tue Jun 17, 2008 4:28 pm)

Just quoting the documentation without real knowledge:

r.resamp.rst - Reinterpolates and computes topographic analysis from input raster map to a new raster map (possibly with different resolution) using regularized spline with tension and smoothing.

r.resamp.interp resamples an input raster map by interpolating between the neighboring cells via a selectable resampling algorithm. All cells present in the neighborhood of the input raster cell must be non-null to generate a non-null cell in the output raster map. A choice of three interpolation methods is available; each uses the weighted values of a different number of adjacent cells in the input map to determine the value of each cell in the output map as follows:
nearest neighbour (1 cell)
bilinear (4 cells)
bicubic (16 cells)
This module is intended for reinterpolation of continuous data to a different resolution rather than for interpolation from scattered data (use the v.surf.* modules for that purpose).

And there are even more similar modules...


Hope this might help, Jorre


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by martin (Posted Mon Jun 16, 2008 3:07 pm)

Hello

I am fascinated by QGIS 0.10 on OS 10.4.11. Congratulation!

However, when ditizing a polygone the moving cursor stretches a white area that blankets layers below. Therefore it becomes impossible to locate vertex points. It must be a refreshing view problem, since the white polygone disappears when quickly moving to another application and back to QGIS. Has anybody a solution to this minor but devaluating problem?

Thanks.


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by asus1 (Posted Mon Jun 16, 2008 9:05 am)

Just for general interest - QGIS with ecw support for Opensuse 11, 10.3 etc

see: http://teodori.org/repository/grass.html

Also if others are not aware it maybe useful to check http://www.nabble.com/Quantum-GIS-f4139.html for qgis info/devel.


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by Coy (Posted Sun Jun 15, 2008 12:17 am)

Hi, I`ve been working with SRTM GeoTIFF files downloaded from http://seamless.usgs.gov/
I`ve been able to create contour lines and shaded relieves by importing the raster to GRASS throught the GDAL import option but the Raster resolution is quite bad.
Is it possible to improve the raster resolution from QGIS through the GRASS Plugin?

Thanks!!


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by sephib (Posted Sat Jun 14, 2008 11:54 pm)

Hi,
firstly I would like to stat that I've had no problem printing in the previous versions.

Currently I am not able to add a map canvas (or any other item - legend etc.) to the map. when i press on it - it seems not to stay pressed....

any suggestions?

thanks

sephi


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by otternase (Posted Sat Jun 14, 2008 4:00 pm)

Hi

I'm happy to hear it works now!

I've changed a few little things now, besides a "Stay-on-top" and masking the region to paint I have put accept and cancel on the enter/escape keys. Probably this is more intuitive.

There is also a "very colourful" icon, but probably someone else can provide a better one?

Ciao
Markus


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by gvaf (Posted Sat Jun 14, 2008 10:11 am)

I have compiled successfully the QGIS 0.11.0 in Windows XP using Microsoft Visual Studio 2005 .

When I am running the program and connecting to PostGre/PostGIS, If you click to load some tables (more than one) there is a crash and program terminates abnormally.

How to fix it:
In file "qgsdbsourceselect.cpp"
Line 338:
change the "if" statement to

if(schemaName!=currentSchema)
{
query = "\"" + schemaName + "\".";
}
else query = "";

The problem was that the stringlist concatenates multiple tables and the result was a crash...
The problem solved I do not know if there are any side effects of my solution....

George


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