Splitting multiple Linestrings into 1 metre parts with GeoPandas shapely

Question

I have a GeoPandas dataframe which contains many rows and also a column named 'geometry' with the following input:

geometry        LINESTRING (445125.050522556 5536587.67127983, 445124.450035...

I want to get a new dataframe which splits the old one into equal 1 metre brackets.

Is that possible? There are some topics about these question but none of them worked well... How can I get it to work?

Here is my code:

from shapely.geometry import Point, LineString import
matplotlib.pyplot as plt import math

line_strings=[LineString([(10,20),(50,70)]),
              LineString([(11,22),(72,80)]),
              LineString([(32,11),(90,96)]),
              LineString([(32,34),(37,38)]),
              LineString([(50,60),(80,90)])]

split_len = 1 
coor_list = []
for i in range(len(line_strings)):
    Y1 = line_strings[i].coords.xy[0][0]
    X1 = line_strings[i].coords.xy[1][0]
    Y2 = line_strings[i].coords.xy[0][1]
    X2 = line_strings[i].coords.xy[1][1]

    lenght = ((X1 - X2) ** 2 + (Y1 - Y2) ** 2) ** (1 / 2)
    list_name = 'line_parts_coor' + str(i)
    list_name = []

    if lenght <= split_len:
        line = LineString([(Y1, X1), (Y2, X2)])
        list_name.append(line)
    else:
        AB = math.atan((Y2 - Y1) / (X2 - X1))

        YT = Y1 + split_len * math.sin(AB)
        XT = X1 + split_len * math.cos(AB)

        for j in range(int(lenght / split_len) + 1):
            YT = Y1 + split_len * j * math.sin(AB)
            XT = X1 + split_len * j * math.cos(AB)
            last_lenght = ((XT - X2) ** 2 + (YT - Y2) ** 2) ** (1 / 2)

            if last_lenght <= split_len:
                line = LineString([(YT, XT), (Y2, X2)])
                list_name.append(line)
            else:
                YT2 = Y1 + split_len * (j + 1) * math.sin(AB)
                XT2 = X1 + split_len * (j + 1) * math.cos(AB)
                line = LineString([(YT, XT), (YT2, XT2)])
                list_name.append(line)

    for k in range(len(list_name)):
        YL1 = list_name[k].coords.xy[0][0]
        XL1 = list_name[k].coords.xy[1][0]
        YL2 = list_name[k].coords.xy[0][1]
        XL2 = list_name[k].coords.xy[1][1]
        plt.plot([YL1, YL2], [XL1, XL2], label='line ' + str(i) + '-' + str(k), marker='o')
        coor_list.append('line ' + str(i) + '-' + str(k)+ ' ['
                         + str(YL1) + ','
                         + str(XL1) + ','
                         + str(YL2) + ','
                         + str(XL2)+']')

    plt.legend()
    plt.show()

print(coor_list)

Answer 1

You can use this script:

Steps:

1. Make an empty list
2. Iterate over rows
3. Split the line
4. Add the split part to the list
5. Make a GeoDataFrame from the list.

from shapely.geometry import  LineString
import geopandas as gpd
import math

line_strings=[LineString([(10,20),(50,70)]),
              LineString([(11,22),(72,80)]),
              LineString([(32,11),(90,96)]),
              LineString([(32,34),(37,38)]),
              LineString([(50,60),(80,90)])]

source_gdf = gpd.GeoDataFrame(line_strings, columns=["geometry"])

split_len = 1
data = []
for i, line in source_gdf.iterrows():
    geom = line["geometry"]
    Y1 = geom.coords.xy[0][0]
    X1 = geom.coords.xy[1][0]
    Y2 = geom.coords.xy[0][1]
    X2 = geom.coords.xy[1][1]

    length = ((X1 - X2) ** 2 + (Y1 - Y2) ** 2) ** (1 / 2)

    if length <= split_len:
        new_line = LineString([(Y1, X1), (Y2, X2)])
        data.append([f"line {i} - 0", new_line])
    else:
        AB = math.atan((Y2 - Y1) / (X2 - X1))

        YT = Y1 + split_len * math.sin(AB)
        XT = X1 + split_len * math.cos(AB)

        for j in range(int(length / split_len) + 1):
            YT = Y1 + split_len * j * math.sin(AB)
            XT = X1 + split_len * j * math.cos(AB)
            last_length = ((XT - X2) ** 2 + (YT - Y2) ** 2) ** (1 / 2)

            if last_length <= split_len:
                new_line = LineString([(YT, XT), (Y2, X2)])
                data.append([f"line {i} - {j}", new_line])
            else:
                YT2 = Y1 + split_len * (j + 1) * math.sin(AB)
                XT2 = X1 + split_len * (j + 1) * math.cos(AB)
                new_line = LineString([(YT, XT), (YT2, XT2)])
                data.append([f"line {i} - {j}", new_line])

gdf = gpd.GeoDataFrame(data, columns=["line_part", "geometry"]) 
gdf.plot(cmap = "prism", figsize=(8, 8))

Result for split_len = 10: