Detect intersection Turf.js, First and last Position are not equivalent

Question

Utilizing Turf.js version 3.0.12. The function below should return the intersection between the two polygons or null if they do not intersect. The polygons do intersect. I have tried several different polygons and receive the same error:

"Error: First and last Position are not equivalent."

I referenced this example: http://turfjs.org/docs#intersect

checkForIntersection = () => {
    const boundingBox1 = turf.polygon([
      [
        [-11638128.151894445, 4697704.8042823635],
        [-11538591.465504704, 4932847.347657125],
        [-11773734.008879466, 5032384.034046866],
        [-11873270.695269207, 4797241.490672104]
      ]
    ]);

    const boundingBox2 = turf.polygon([
      [
        [-11545948.977350365, 4658759.839788924],
        [-11483057.72508946, 5032936.709591224],
        [-11857234.59489176, 5095827.961852129],
        [-11920125.847152665, 4721651.092049829]
      ]
    ]);

    const intersection = turf.intersect(boundingBox1, boundingBox2);

    console.log("intersection: ", intersection);
  };

Thanks for looking!

I think you have to close your polygons by making the first and last points in the array the same. — C. Braun, Mar 27 '18 at 20:23

score 2 · Accepted Answer · answered Jul 08 '20 at 18:09

this because the first and last point or positions must be same for each polygon. so the boundingBox1 & boundingBox2 will be :

checkForIntersection = () => {
    const boundingBox1 = turf.polygon([
      [
        [-11638128.151894445, 4697704.8042823635],
        [-11538591.465504704, 4932847.347657125],
        [-11773734.008879466, 5032384.034046866],
        [-11873270.695269207, 4797241.490672104],
        [-11638128.151894445, 4697704.8042823635],
      ]
    ]);

    const boundingBox2 = turf.polygon([
      [
        [-11545948.977350365, 4658759.839788924],
        [-11483057.72508946, 5032936.709591224],
        [-11857234.59489176, 5095827.961852129],
        [-11920125.847152665, 4721651.092049829],
        [-11545948.977350365, 4658759.839788924],
      ]
    ]);

    const intersection = turf.intersect(boundingBox1, boundingBox2);

    console.log("intersection: ", intersection);
  };

Detect intersection Turf.js, First and last Position are not equivalent

1 Answers1