Hi,
Ok what you want to do is to sample a raster with data points (and not
merge two rasters). This mean you have a csv of points and a raster
with values. You want the values of the raster to be added to a column
in the csv. When you open both layers, do they appear to be well
placed in space (georeferenced) and one on top of the other? If not,
right click on the layer in the layer panel and go to "set CRS/Set layer
CRS". Once both layers are in the correct CRS, they should be one on
top of the other.
Then used the Processing tool (sample raster values) or install the
Point Sampling tool. Both are plugins that need to be activated under
the plugins menu but the Point Sampling tool will need to be installed
first. You will need to save the CSV in another format because you
cannot write to a CSV. Use Shp or better, Geopackage.
Nicolas
On 2020-05-06 10:48 a.m., Nikos Benos wrote:
Dear Nicolas,
I have used the following methodology
https://www.qgistutorials.com/en/docs/3/sampling_raster_data.html
It works fine, but the problem is that the coordinates of the tiff
file are in different scale than the coordinates of the csv file.
If I convert my csv file (list of points with their coordinates) in
raster file, how will I combine 2 raster files to produce an excel file?
Thank you very much in advance for your help.
Best,
Nikos
Στις Τετ, 6 Μαΐ 2020 στις 4:36 μ.μ., ο/η Nicolas Cadieux
<nicolas.cadi...@archeotec.ca <mailto:nicolas.cadi...@archeotec.ca>>
έγραψε:
Hi,
You can save a file and reproject it by changing the coordinates
reference system (CRS). That would change the coordinates (and
the data dependent on the method used). However, the is the csv a
vector file (a file with a list of points for example) or is it a
true raster file (a matrix). If it’s a vector file, you will need
to change it as a raster. Look for rasterize or « vector to
raster ». Google it to understand the differences between raster
and vector.
Nicolas Cadieux
Ça va bien aller!
Le 6 mai 2020 à 02:22, Nikos Benos <nbe...@uoi.gr
<mailto:nbe...@uoi.gr>> a écrit :
---------- Forwarded message ---------
Από: *Nikos Benos* <nbe...@uoi.gr <mailto:nbe...@uoi.gr>>
Date: Τρί, 5 Μαΐ 2020 στις 12:25 μ.μ.
Subject: Question
To: <qgis-user@lists.osgeo.org <mailto:qgis-user@lists.osgeo.org>>
Dear Sir or Madam,
I hope all is well with you. I have converted a png file to a
tiff file (when I attached it to the e-mail, the e-mail became
too big and was not sent). I have been trying to combine the tiff
file with a csv file with no success. The reason is that the
coordinate units are different between the 2 files.
Since I have constructed myself the csv file, is there any way to
transform the coordinate units of the png file to make them
compatible to those of the csv file?
Thank you very much in advance for our help and I am sorry if
this is a vdery simple question, but I am very new to QGIS.
Best regards,
Nikos Benos
--
Dr Nikos Benos
Associate Professor
Department of Economics
University of Ioannina
University Campus
45110 Ioannina
GREECE
Tel: +30-26510-05955
Fax: +30-26510-05092
e-mail:nbe...@uoi.gr <mailto:nbe...@uoi.gr>
--
Dr Nikos Benos
Associate Professor
Department of Economics
University of Ioannina
University Campus
45110 Ioannina
GREECE
Tel: +30-26510-05955
Fax: +30-26510-05092
e-mail:nbe...@uoi.gr <mailto:nbe...@uoi.gr>
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--
Dr Nikos Benos
Associate Professor
Department of Economics
University of Ioannina
University Campus
45110 Ioannina
GREECE
Tel: +30-26510-05955
Fax: +30-26510-05092
e-mail:nbe...@uoi.gr <mailto:nbe...@uoi.gr>
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