[Qgis-user] Help converting State

Andrea Giudiceandrea andreaerdna at libero.it
Tue Jan 25 04:16:21 PST 2022


> Bighouse Productions 
> <https://www.mail-archive.com/search?l=qgis-user@lists.osgeo.org&q=from:%22Bighouse+Productions%22>Mon, 
> 24 Jan 2022 18:37:41 -0800 
> <https://www.mail-archive.com/search?l=qgis-user@lists.osgeo.org&q=date:20220124>
>
> Hi Chris et al. here's a video showing the steps I'm following -- can
> someone pinpoint what I'm doing wrong?
> https://vimeo.com/669657507/e84405ce12
Hi Doug,
If I understand correctly your "issue" looking at the video, there is 
probably a misunderstanding about how csv / vector layers / reprojection 
work.

A GIS vector layer stores information about the features geometries (the 
coordinates of each point or vertex) and the features alphanumeric 
attributes (the fields and their values).

A csv file stores alphanumeric attributes.

When you import the csv file in QGIS , since some fields contain values 
representing the coordinates of a point,  it becomes a vector layer in 
which the features geometries are created, on importing, from the values 
(the coordinates) contained in such fields and the features attributes 
are the same attributes stored in the csv file.

Reprojecting a vector layer from a CRS to another one only changes the 
features geometries and not the features attributes.

Exporting a vector layer (with default options) to a csv file only saves 
its alphanumeric attributes.

Does this make sense to you?

Do you need to transform the coordinates values relative to a CRS stored 
in the EAST and NORTH fields of your csv file to the coordinates values 
relative to another CRS and update your EAST and NORTH fields or add new 
fields with the new values and save it as another csv file?

There various ways to obtain the some result.

For example:
- you can select the GEOMETRY: AS_XY layer option in order to add X an Y 
fields to the exported CSV in which the coordinates values are stored 
relative to the CRS set in the CRT option.
- or you can reproject the layer (Processing tool: "Reproject layer") 
and than use the Field Calculator to add new field or updated the EAST 
and NORTH fields with the new coordinates of the points and then save 
the layer to a CSV file with the default options.
- or you can use the Processing tool "Add X/Y fields to layer" to add X 
and Y fields with the coordinates values relative to the desired CRS and 
then save the layer to a CSV file with the default options.

Regards.

Andrea Giudiceandrea
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