[Qgis-user] Antarctic polar stereographic graticules (composer)
Nicolas Cadieux
nicolas.cadieux at archeotec.ca
Thu Jun 2 05:51:13 PDT 2016
Hi,
I am trying to understand. You said " I had some Antarctic polar stereographic data and when applying a
WGS-84 long-lat grid in map composer" .
That means you have 2 CRS. One in Polar stereographic and the graticule are in WGS84. You are therefore reprojecting on the fly. That is always a bad idea when mixing two very different CRS as this sometimes creates crazy things like missing lines, exploding line and odd looking stuff.
To solve this, save everything in the same CRS and make sure the grid in the map composer and the project are in the same CRS as all the data.
"As you say, the other option is to generate a vector grid and densify, however you then lose the label function that you have in the composer."
You can probably create a transparent grid in the map composer but use opaque labels.
If I am not understanding properly, send a screen shot or a a zipped project.
Nicolas
On Jun 2, 2016 01:36, "Lester Anderson [via OSGeo.org] " <ml-node+s1560n5269466h7 at n6.nabble.com> wrote:
Hi Nicolas, The grid I have is already projected in an Antarctic South polar, so that was not the issue with on the fly projection. I just fail to understand why the graticules in map composer seem odd in Polar views. As you say, the other option is to generate a vector grid and densify, however you then lose the label function that you have in the composer. Coastline data reproject fine on both South and North Polar views. Will keep investigating this one Lester On 1 June 2016 at 17:40, Nicolas Cadieux < [hidden email] > wrote: Hi,
When crossing the equator, 0 or 180 degrees, you will always have difficulty reprojecting shapes on the fly. That is what you are doing. Your project is in polar but you are creating a grid in WGS84.
That grid is being reprojected on the polar project. That will always happen when you try mix a more "global" CRS and a "local" projection.
Make sure everything is in the same CRS. (Save as.. change CRS).
Do not reprojection anything including the grids in the map composer.
If that does not work, you could always create the grid that you need (You may need to densify the shape). Save it in the correct CRS. You could then probably add a transparent grid in the map composer. This way, you would get the coordinates around the map but not the problems with the grid.
Hope this helps.
Nicolas
On Jun 1, 2016 11:14 AM, Lester Anderson < [hidden email] > wrote: Hi Nicolas, The problem is not so much with the grid as that displays fine. The issue crops up with the map composer, and even with the grid as WGS-84 the same problem persists. Looked at both North and South polar views and the 180 graticule is always missing irrespective of the increment used. The latitude lines do not change and are clear line segments; these should be smoother. Data that are in UTM and with WGS-84 graticules look fine (smooth latitude lines). Is there an issue with Polar views and graticules? Lester On 1 June 2016 at 11:41, Nicolas Cadieux < [hidden email] > wrote: Hi,
Try saving the layer in WGS-84. Then make sure the project is also in the same projection. It can help sometimes to make a spatial index.
Keep me posted.
Nicolas
On Jun 1, 2016 05:35, "Lester Anderson [via OSGeo.org] " < [hidden email] > wrote:
Hello,
I had some Antarctic polar stereographic data and when applying a
WGS-84 long-lat grid in map composer it generated most of the
longitude lines (180 missing), and very crude latitude lines (clearly
visible straight line segments).
Is there any way to improve the latitude lines?
Lester
Tested in 2.10, 2.12, 2.14
_______________________________________________
Qgis-user mailing list
<a href="/user/SendEmail.jtp?type=node&node=5269310&i=0">[hidden email]
List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user Ant2016.jpg (38K) Download Attachment
If you reply to this email, your message will be added to the discussion below:
http://osgeo-org.1560.x6.nabble.com/Antarctic-polar-stereographic-graticules-composer-tp5269310.html
To start a new topic under Quantum GIS - User, email [hidden email]
To unsubscribe from Quantum GIS - User, <a href=" http://osgeo-org.1560.x6.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=4125267&code=bmljb2xhcy5jYWRpZXV4QGFyY2hlb3RlYy5jYXw0MTI1MjY3fDYzNDQ4MjQxNg== ;">click here.
<a href=" http://osgeo-org.1560.x6.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml " style="font:9px serif">NAML
View this message in context: Re: Antarctic polar stereographic graticules (composer)
Sent from the Quantum GIS - User mailing list archive at Nabble.com. _______________________________________________
Qgis-user mailing list
[hidden email]
List info: http://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
_______________________________________________
Qgis-user mailing list
[hidden email]
List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
If you reply to this email, your message will be added to the discussion below:
http://osgeo-org.1560.x6.nabble.com/Antarctic-polar-stereographic-graticules-composer-tp5269310p5269466.html
To start a new topic under Quantum GIS - User, email ml-node+s1560n4125267h38@n6.nabble.com
To unsubscribe from Quantum GIS - User, click here .
NAML
--
View this message in context: http://osgeo-org.1560.x6.nabble.com/Antarctic-polar-stereographic-graticules-composer-tp5269310p5269548.html
Sent from the Quantum GIS - User mailing list archive at Nabble.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20160602/2bfa47a2/attachment.html>
More information about the Qgis-user
mailing list