I'm working on a stormtracking project, and I realized that the longitude sign of some values in my GeoPandas dataframe are wrong; i.e. I need negative longitudes instead of positive ones.
When I trace my storm tracks, I have an ugly horizontal line (the red one) which can be explained by a change in the sign of longitude in geometry.linestring.
For example:
My GeoDataFrame looks like:
DEBUT MEMBER FIN ID VORT PRES CIRC geometry
11 2020112415 0 2020112418 49 78.0 952.88 0.0 LINESTRING (-175 60, -174.75 61.5)
12 2020112418 0 2020112421 49 80.0 950.16 0.0 LINESTRING (-174.75 61.5, -175.25 62.5)
13 2020112421 0 2020112500 49 81.0 948.5 0.0 LINESTRING (-175.25 62.5, -176.5 63.5)
14 2020112500 0 2020112503 49 81.0 946.03 0.0 LINESTRING (-176.5 63.5, -177.75 64)
15 2020112503 0 2020112506 49 79.0 945.21 0.0 LINESTRING (-177.75 64, -179.5 64.25)
16 2020112506 0 2020112509 49 77.0 945.48 0.0 LINESTRING (-179.5 64.25, 178.75 64.5)
Then I'm trying to change the last row with spent many hours on it:
16 2020112506 0 2020112509 49 77.0 945.48 0.0 LINESTRING (-179.5 64.25, 178.75 64.5)
Is there any function in GeoPandas to easily manipulate the coordinates?
I'm turning around ... here's my last attempt to modify longitudes:
def swap2(x):
coords = list(x.coords)
coords = [Point(-t[0], t[1]) for t in coords]
return LineString(coords)
tempete=tempete.geometry.map(swap2)
This is what I tried to do. I had never used geopandas before, now I can see how to handle linesting.
Unfortunately, I was digging in the wrong direction. I think my longitudes are correct. If I change my longitudes by simply applying a sign - on negative values, I naturally lose storms for longitudes above 0deg ... I have to find a solution to correctly visualize storms that go from -180gW to 180degE.
Before swap2 function:
After swap2:
