# Baseline drawing line between latitude longitudes

I am drawing the start / end locations for a tornado. The csv file has data such that:

``````TouchDownLat TouchDownLong LiftoffLat LiftoffLong
31.53         -97.15       31.74      -96.88
46.45         -100.67      46.67      -100.47
43.1          -83.85       43.17      -83.42
```

```

etc...

What I did was take each latitude and longitude and split it into a numpy array as such:

``````import matplotlib.pyplot as plt
import csv
import numpy as np
from mpl_toolkits.basemap import Basemap
with open(fname, 'rb') as f:
w = csv.reader(f, delimiter = ',')
for i, line in enumerate (w):
if i == 0 or line[0:4] not in str(range(2007,2018)):
pass
else:
lat_td.append(line)
long_td.append(line)
lat_lift.append(line)
long_lift.append(line)

touchdown = np.array([[lat_td], [long_td]])
lift = np.array([[lat_lift], [long_lift]])
```

```

For the basemap, I find the max / min for the whole lat / long, so it makes the map to cut out states that did not have a tornado (for example: I don't want to see California when looking at EF-5 tornado locations)

``````m = Basemap(projection = 'merc', llcrnrlat=float(min(lat_td)) - 2,\
urcrnrlat=float(max(lat_lift)) + 2, llcrnrlon=float(max(long_td)) - 2,\
urcrnrlon=float(min(long_lift)) + 2,lat_ts=40,resolution='l')
m.drawcoastlines()
m.fillcontinents(color='white')
m.drawmapboundary(fill_color='white')
m.drawstates(color='black')
m.drawcountries(color='black')
plt.title("#wedgez")
```

```

So now the question is: I am looking to plot a tornado track using lat / long on a numpy array. How can i do this?

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If I understand correctly, you are looking for a way to plot the path given the coordinates of the path points. Then you can build the path like this:

``````m = Basemap(projection = 'merc', llcrnrlat=float(min(lat_td)) - 2,\
urcrnrlat=float(max(lat_lift)) + 2, llcrnrlon=float(max(long_td)) - 2,\
urcrnrlon=float(min(long_lift)) + 2,lat_ts=40,resolution='l')

lat = [the list of lat coordinates here]
lon = [the list of lon coordinates here]

x, y = m(lon, lat)
m.plot(x, y, 'o-', markersize=5, linewidth=1)

m.drawcoastlines()
m.fillcontinents(color='white')
m.drawmapboundary(fill_color='white')
m.drawstates(color='black')
m.drawcountries(color='black')
plt.title("#wedgez")
plt.show()
```

```
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