Graphing points on a map but the error code is "ValueError: 'box_aspect' and 'fig_aspect' must be positive"

Question

I am trying to plot a collection of points onto a graphic of King County, WA.

I can show the graphic with the following code:

fig, ax = plt.subplots(figsize = (15,15))
kings_county.plot(ax=ax)

This gives me the graphic. I then read in the points from the lat/long of a csv I load.

df = pd.read_csv('kc_house_data_train.csv')
crs = {'init': 'epsg:4326'}

And this puts all of the points in a new dataframe

geometry = [Point(x,y) for x,y in zip(df.lat,df.long)]

geo_df = gpd.GeoDataFrame(df, # specifify your dataframe
                          crs = crs, # this is your coordinate system
                          geometry = geometry) # specify the geometry list we created

However, when I do this

fig, ax = plt.subplots(figsize = (40,40))
kings_county.plot(ax=ax, alpha = 0.4, color = 'grey', aspect = 'auto')
geo_df[geo_df.price >= 750000].plot(ax = ax , markersize = 20, color = 'blue',marker = 'o',label = 'pricey')
geo_df[geo_df.price < 750000].plot(ax = ax , markersize = 20, color = 'blue',marker = 'o',label = 'pricey')
plt.legend()

It just returns an error: ValueError: 'box_aspect' and 'fig_aspect' must be positive Not sure why loading the graphic works but the added points makes it break.

Just looking for understanding of this and a fix, if you can. Thanks

Counterpoint

Running into this same error now, did you ever find a work around? – Grefer

Yes, I changed aspect to 1 for both plot entries. Warning stopped and graph was plotted. – Counterpoint

Running into this problem as well now. How do you change the aspect to 1 for both plot entries? – Anitraaniweta

FWIW, I set the box aspect using: matplotlib.org/api/_as_gen/… which I had to upgrade to matplotlib 3.3 – Anitraaniweta

Note that passing aspect=1 as a parameter to .plot() to fix this is wrong and dangerous. It's merely papering over a data problem by suppressing the symptom. If you've confused lat and lon, your results will simply be wrong. – Malarkey

Answer 1

I solved this issue simply setting gdf.plot(aspect=1). It didn't happen in previous versions of geopandas, but it suddenly started happening and I figured it was simply this parameter, as it can be read in the error you gave.

Comber

Answer 2

I had this exact problem and found out the Shapely polygon (x,y) coordinates are (longitude, latitude), so I just had to switch the lat/long order in the zip function and everything worked properly. Thanks to this thread for the solution.

Jacy

Had the same problem and this is the thing that solved my problem! This should be marked as the correct answer. – Liability

Answer 3

This is a classic case of a mismatch between a stated CRS and the actual geometry. Note the OP rolled their own GeoDataFrame having created their own geometry list and got lat lon transposed. Thus there would be such a mismatch.

Note the documentation for creating a GeoDataFrame that way gives the example

gdf = geopandas.GeoDataFrame(
    df, geometry=geopandas.points_from_xy(df.Longitude, df.Latitude))

and states

We use geopandas points_from_xy() to transform Longitude and Latitude into a list of shapely.Point objects and set it as a geometry while creating the GeoDataFrame. (note that points_from_xy() is an enhanced wrapper for [Point(x, y) for x, y in zip(df.Longitude, df.Latitude)])

Note the transposition of the order of lat/lon in the zip() relative to the OP.

I found this thread having encountered the error after loading a .gpkg in the same python environment as had been happily working before. It's a data problem, not a geopandas version issue. In my case, I checked the data bounds after reading it in and got

wensum_manual.total_bounds
array([607560.35533316, 324060.06511765, 615703.81324167, 327821.37222748])

and then checking the stored CRS, I got

wensum_manual.crs
<Geographic 2D CRS: EPSG:4326>
Name: WGS 84
Axis Info [ellipsoidal]:
- Lat[north]: Geodetic latitude (degree)
- Lon[east]: Geodetic longitude (degree)
Area of Use:
- name: World.
- bounds: (-180.0, -90.0, 180.0, 90.0)
Datum: World Geodetic System 1984 ensemble
- Ellipsoid: WGS 84
- Prime Meridian: Greenwich

Hang on, those bounds don't look like lat/lon! Yes, the aspect=1 flag suppressed the error and allowed the plot to render, but it's not the correct fix. Here I corrected the erroneous CRS:

wensum_manual = wensum_manual.set_crs(epsg=27700, allow_override=True)

Malarkey