56
votes
Converting Pandas DataFrame to GeoDataFrame
Update 201912: The official documentation at https://geopandas.readthedocs.io/en/latest/gallery/create_geopandas_from_pandas.html does it succinctly using geopandas.points_from_xy like so:
gdf = ...
- 1,751
55
votes
Finding nearest point in other GeoDataFrame using GeoPandas
If you have large dataframes, I've found that scipy's cKDTree spatial index .query method returns very fast results for nearest neighbor searches. As it uses a spatial index it's orders of magnitude ...
- 659
31
votes
Accepted
Finding nearest point in other GeoDataFrame using GeoPandas
You can directly use the Shapely function Nearest points (the geometries of the GeoSeries are Shapely geometries):
from shapely.ops import nearest_points
# unary union of the gpd2 geomtries
pts3 = ...
- 55.2k
24
votes
Accepted
Shapely coordinate sequence to GeoDataFrame
Make a shapely polygon geometry from coordinate pairs.
Pass the polygon to GeoDataFrame constructor as a list.
import geopandas as gpd
from shapely.geometry import Polygon
coords = [(151....
- 77.8k
22
votes
Accepted
Reading raw data into geopandas
You can pass the json directly to the GeoDataFrame constructor:
import geopandas as gpd
import requests
data = requests.get("https://data.cityofnewyork.us/api/geospatial/arq3-7z49?method=export&...
- 67.7k
20
votes
Finding nearest point in other GeoDataFrame using GeoPandas
As of v0.10.0 geopandas supports sjoin_nearest natively - see here.
Example:
Get the nearest distances between points of two different GeoDataFrames or within one GeoDataFrame. Note that you should ...
- 323
19
votes
Change marker size in plot with GeoPandas
In geopandas >= 0.3 (released September 2017), the plotting of points is based on the scatter plot method of matplotlib under the hood, and this accepts a variable markersize.
So now you can actually ...
- 3,933
17
votes
Accepted
TypeError: Input geometry column must contain valid geometry objects
I tested the following and works fine:
from shapely import wkt
import pandas as pd
df = pd.DataFrame(
{'name': ['testname', 'testname'],
'geom': ['MULTIPOLYGON (((21.78 40.36, ... 21.77 40....
- 567
16
votes
Accepted
Quick way to get WKT from a GeoDataFrame's geometries in GeoPandas?
UPDATE: As of GeoPandas 0.9, there is a to_wkt method.
mydf['wkt'] = mydf.geometry.to_wkt()
Yes, there is to_wkt method in semi-private array module. I think it should be public in future, will have ...
- 2,447
14
votes
Accepted
GeoPandas to_file() saves GeoDataFrame without coordinate system
I have come across this behavior before.
You need to explicitly pass the well known text (crs_wkt) string to the to_file() method. The string will then get passed to fiona.open(), which writes out ...
- 3,933
12
votes
Accepted
Merging a geodataframe and pandas dataframe based on a column
You should specify a common key using on parameter. I removed merged_ prefix for legibility.
df = spatial_df.merge(tab_df, on='mukey', how='left')
# df = tab_df.merge(spatial_df, on='mukey', how='...
- 77.8k
11
votes
Accepted
Adding elevation, name and description in GeoJSON when converting DataFrame with Python
Using what i learned from the answer of @gene this solution avoids the use of iterrows because iterrows have performance issues.
Valid for Python 3.X
import pandas as pd
import geojson
def ...
- 293
11
votes
Finding distance of consecutive points in a GeoPandas data frame
This is how I would do it
import pandas as pd
import geopandas as gpd
df = pd.DataFrame()
df['lat'] = [42, 42.1, 43, 43.2, 43.9]
df['lon'] = [-120, -119, -118.2, -118, -117.2]
gdf = gpd.GeoDataFrame(...
- 211
11
votes
Accepted
"Copy" Image coordinates to another image that is nd.array
Save result array (rf_array) as in the following lines:
rf_array = df_join['Prediction'].values # returns numpy.ndarray
rf_array = rf_array.reshape(img.shape[0], img.shape[1])
# rf_array = rf_array....
- 77.8k
11
votes
Accepted
Creating polyline from list of QgsPoints using PyQGIS
Solution using sample data to run in QGIS Python Editor:
import pandas as pd
# Creating sample data
dato = pd.DataFrame(data = [[0, 0], [2, 4], [10, 10]])
# Rename column headers
dato.columns = ['...
- 3,439
10
votes
Accepted
Plotting a CSV with coordinates one row at a time via GeoPandas
The following script saves an image for each earthquake point in a single plot.
from shapely.geometry import Point
from geopandas import GeoDataFrame
import geopandas as gpd
import pandas as pd
...
- 77.8k
9
votes
Finding nearest point in other GeoDataFrame using GeoPandas
Figured it out:
def min_dist(point, gpd2):
gpd2['Dist'] = gpd2.apply(lambda row: point.distance(row.geometry),axis=1)
geoseries = gpd2.iloc[gpd2['Dist'].argmin()]
return geoseries
Of ...
- 1,623
9
votes
Accepted
Getting elevation for multiple lat long coordinates in Python
Don't know if this is the simplest way, but it saves gathering elevation data. The USGS-National Map has a REST service that you can use to query elevation for lat/lon coords.
Service url:
https://...
- 1,173
9
votes
Accepted
Creating QgsVectorLayer from Pandas dataframe
Your method is the simplest. However, there is an alternative by creating a new layer in QGIS and completing it by browsing your dataframe pandas.
import pandas as pd
# Declaration of my pandas ...
- 4,110
9
votes
Attribute Table into pandas DataFrame-PyQGIS
You can try:
import pandas as pd
lyr = QgsProject.instance().mapLayersByName('ok_ak_riks')[0]
#List all columns you want to include in the dataframe. I include all with:
cols = [f.name() for f in lyr....
- 76.2k
9
votes
Accepted
Joining two Pandas DataFrames based on lat, long as fields
Create Pandas DataFrame
Create GeoPandas DataFrame using #1
Create Buffer for Points
sjoin both GeoDataFrame
df1 = pd.DataFrame({
'name': ['post', 'sutter', 'oak'],
'Lat': [37.788151, ...
- 1,065
8
votes
Accepted
Building GeoDataFrame row by row
I don't think that a row by row building would have better performance. I've tested.
Result:
import geopandas as gpd
import pandas as pd
from shapely.geometry import Point
d = {'007': {'name': 'A', '...
- 77.8k
8
votes
Accepted
Read a GDB table into a pandas dataframe in ArcPy
You can use da.SearchCursor:
import arcpy
import pandas as pd
table = r"C:\GIS\ArcMap_default_folder\Default.gdb\grids"
columns = [f.name for f in arcpy.ListFields(table) if f.type!="...
- 76.2k
7
votes
Making shapefile from Pandas dataframe?
For ArcMap you need to define the Projection before exporting to Shapefile.
import geopandas
df = geopandas.GeoDataFrame(df, geometry='geometry')
# proj WGS84
df.crs= "+proj=longlat +ellps=WGS84 +...
- 171
7
votes
Geopandas: Write layer back into GeoDataBase
As with Fiona where you can specify the driver when you save a layer, you can do the same thing with GeoPandas (Writing Spatial Data)
GeoDataFrames can be exported to many different standard ...
- 55.2k
7
votes
Accepted
Groupby Ploting - give each plot title/name
If you want to represent the continents side by side, you have to create subplots on the same fig. To do so, you can iterate through your group of continents. Here is an example:
import geopandas as ...
- 332
7
votes
Error when converting a pandas DataFrame to a GeoDataFrame
Your lon, lat cols are object types. Cast them to floats:
geometry = geopandas.points_from_xy(df.longitude.astype('float32'), df.latitude.astype('float32'))
#OR
geometry = geopandas.points_from_xy(df[...
- 67.7k
7
votes
Accepted
Mapping multiple polygons on Folium
If you use the data of Converting a column with coordinates in Pandas to GeoPandas, there is a problem with your location value or with your data
The data in the GeoDataFrame
x1,y1,x2,y2 = gdf['...
- 55.2k
7
votes
Accepted
Pandas DataFrame to GeoDataFrame with Polygon geometry using groupby and lambda
Instead of using apply this can be done using the agg method with named aggregations. The only thing is that agg cannot yet operate on multiple columns, so the points must be condensed to a single ...
- 1,867
7
votes
Accepted
Converting Pandas column with featurecollection to GeoJSON
You can use the following code. Just specify json_string_column and output file path.
import json
import pandas as pd
import geopandas as gpd
# df = YOUR DATAFRAME
json_string_column = "...
- 77.8k
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