Some problem with this code shown below ( it doesn't shows any kind of error in QGIS python console but it is not responding) , When I tried to run it in Visual code it shows error
" Exception has occurred: ModuleNotFoundError
No module named 'qgis'
File "C:\Users\xsurpr\Desktop\WEIBULL\Hojddatapython.py", line 3, in
from qgis.core import QgsRasterLayer, QgsApplication "

code :

from qgis.core import QgsRasterLayer, QgsApplication
from osgeo import gdal

import numpy as np

starting a QGIS application

qgishome = 'C:/OSGeo4W64/apps/qgis'
app = QgsApplication ([], True)
QgsApplication.setPrefixPath(qgishome, True)
QgsApplication.initQgis()

Loading raster layer

Name = 'C:/temp3/bergyta_hojd_50x50m.tif'
bigraster = gdal.Open(Name)

band1 = bigraster.GetRasterBand(1).ReadAsArray()
print = (band1)

Thanks in advance

I've managed to write a working loop that (I think) calculates the distance between each vector point of one layer val_lokaler and each vector point of another layer centroids .

for x in val_lokaler.getFeatures():
    x_geom = x.geometry()
    for y in centroids.getFeatures():
        y_geom = y.geometry()
        dist_m = y_geom.distance(x_geom)
        print(x.id(), y.id(), dist_m)

However, what I want to do is calculate the distance between each point in val_lokaler and one specific point in centroids . The point it should calculate the distance from shares a common field and value in both layers (VALDISTRIK = e.g. 1234). I think I only need one loop for this (not the nested loop) but I can't figure out how to access the corresponding points in the centroid layer.

Thanks for your help!

Hello (unsure which language to use, but someone else may be interested I dont know)

I am struggling with how to make get unique attribues from a selected field from a vector layer into a scroll list

So in the box called Class: in the picture below i would like to be able to select fields from the selected attributes

# Reharvested code from UAVPrepare

        self.layerComboManagerPoint = QgsMapLayerComboBox(self.dlg.comboBoxVector)
        self.layerComboManagerPoint.setCurrentIndex(-1)
        self.layerComboManagerPoint.setFilters(QgsMapLayerProxyModel.PolygonLayer)
        self.layerComboManagerPoint.setFixedWidth(175)

        self.layerComboManagerPointField = QgsFieldComboBox(self.dlg.comboBoxField)
        self.layerComboManagerPointField.setFilters(QgsFieldProxyModel.AllTypes) # All types?
        self.layerComboManagerPoint.layerChanged.connect(self.layerComboManagerPointField.setLayer)

        # Somewhere here I am looking for like
        self.layerComboManagerPointFieldAttribute = QgsFieldComboBox(self.dlg.comboBoxAttribute)
        self.layerComboManagerPointFieldAttribute.setFilters(QgsFieldProxyModel.AllTypes)
        self.layerComboManagerPointFieldAttribute.layerChanged.connect(
                    self.layerComboManagerPointFieldAttribute.setATTRIBUTE(??)) # here i just wrote something 

I might be missing an important step, do you have any tips on google-words or code too search for?

Hi..

Finally I could managed to calculate the area of my polygons ( I had to fix geometries but finally it runs kakaka) for one of the months of my data but now I would like to run the script for other months and plot the graphs with differences. But I am bit confusing of how can I do it. The data as same format (.shp files).

#Loading a vector layer
vlayer = QgsVectorLayer ('c:/Cossa/Thesis_Data/FixedJulyScars_2020.shp', 'FixedJulyScars_2020','ogr')
print(vlayer.isValid())
vlayer2 = QgsVectorLayer ('c:/Cossa/Thesis_Data/DugongScars_Aug20.shp', 'DugongScars_Aug20','ogr')
print(vlayer2.isValid())

check attributes in vector layers

for features in vlayer.getFeatures():
attrs = features.attributes()
print(attrs[0])
for features in vlayer2.getFeatures():
attrs = features.attributes()
print(attrs[0])

geom = features.geometry()
if geom.isMultipart() :
    print (vlayer.name(), ': Warning: Multipart', features. id())
    print (vlayer2.name(), ': Warning: Multipart', features. id())

#vlayer = iface.activeLayer()
caps = vlayer.dataProvider().capabilities()
fields_name = [f.name() for f in vlayer.fields()]

we check if we can add an attribute to the layer

if caps & QgsVectorDataProvider.AddAttributes:
if 'Area' not in fields_name:
vlayer.dataProvider().addAttributes ( [ QgsField ('Area',QVariant.Double) ] )
vlayer.updateFields()
fields_name = [f. name() for f in vlayer.fields()]
fareaidx = fields_name.index ('Area')

calculate area of polygons

if caps & QgsVectorDataProvider.ChangeAttributeValues:
for gFeat in vlayer.getFeatures():
d = QgsDistanceArea()
d.setSourceCrs(vlayer.crs(), QgsProject.instance().transformContext())
d.setEllipsoid (QgsProject.instance().ellipsoid())

for features in vlayer.getFeatures():
geom = features.geometry()
area = [0]
landArea = gFeat ['Area']
if geom.isMultipart():
polyg = geom.asMultiPolygon()
for polyg in polyg:
area = d.measurePolygon(polyg[0])
landArea = area
print(landArea)