Perform spline interpolation on GPS coordinates?

Programming
, , , ,
1

I have GPS coordinates in a CSV file that I use to predict a race track with a regression model. When I plot these coordinates on Google Maps, the curve is not smooth. To make it smooth, I need to use a spline interpolation. But I have no idea how to use it with only longitudes and latitudes as variables.

Example:

Let’s say these are my data:

latitudes = array([58.846563, 58.846573, 58.846586, 58.846601, 58.846618, 58.846637,
                   58.846658, 58.846681, 58.846705, 58.846731])

longitudes = array([9.903741, 9.903733, 9.903724, 9.903713, 9.9037  , 9.903686,
                    9.90367 , 9.903652, 9.903633, 9.903612])

Can I use a spline interpolation to smooth the curve when I plot these coordinates on Google Maps?

2

Yes, you can use a spline interpolation to smooth the curve when plotting these coordinates on Google Maps. Here’s how you can do it in Python:

from scipy.interpolate import splprep, splev
import numpy as np

latitudes = np.array([58.846563, 58.846573, 58.846586, 58.846601, 58.846618, 58.846637,
                      58.846658, 58.846681, 58.846705, 58.846731])
longitudes = np.array([9.903741, 9.903733, 9.903724, 9.903713, 9.9037  , 9.903686,
                       9.90367 , 9.903652, 9.903633, 9.903612])

# Use spline interpolation to fit a curve to the data
tck, u = splprep([latitudes, longitudes], s=0)

# Evaluate the fitted curve at 1000 points
u_new = np.linspace(u.min(), u.max(), 1000)
latitudes_smooth, longitudes_smooth = splev(u_new, tck)

# Plot the original and smoothed data on Google Maps
# (code to plot on Google Maps is not included)

Note that splprep and splev are functions from the scipy.interpolate module that allow you to use spline interpolation to fit a curve to your data and evaluate the fitted curve at new points, respectively. The s parameter in splprep controls the smoothness of the fitted curve; larger values of s result in a smoother curve. In this example, s=0 means that the curve will pass exactly through all the input points. The code to plot the data on Google Maps is not included, but you can use any plotting library that supports plotting latitude and longitude coordinates.