# [SciPy-User] Vector Field Generation

Dan Stowell dan.stowell@eecs.qmul.ac...
Tue Aug 21 04:14:30 CDT 2012

```Hi -

It's not clear to me, if you are "generating" child points or
like you're classifying the child points according to their parent.

Nearest-neighbour search would work fine in your example BUT not in the
space of location [x,y]. it looks like nearest-neighbours in a joint
space of location and velocity [x,y, a * dx, a * dy] would work OK
(where "a" is a scaling factor to weight position-vs-velocity); or even,
just velocity alone.

HTH
Dan

On 20/08/12 10:02, Prashant wrote:
> Hi,
>
> I was googling for this problem where I myself don't know that exact
> term to use for. It could be vector field, follow behaviour, flow field,
> streamlines or anything else.
>
> Please have a look at attached image "vector_field.jpg".
>
> 1. Three black rectangles represent polygons in 2d space.
> 2. Red color points are Master Points/Vectors in 2d space
> 3. Green color points are child points (no vector, only position)
>
> Based on Master points I would like to generate vectors (vector field)
> on child points.
> I have also attached an image (image1.jpg) that shows desired result. In
> this image resulting
> child vectors has smooth transition which is what I am looking for. The
> four white arrows can be considered
> as Master vectors and rest of the points are childrens.
>
> I am not sure if nearest neighbour search algorithm would be used but if
> it's required then we have to consider
> a situation.
> I have pointed out a child point using darker black arrow in
> vector_field.jpg. If we calculate
> nearest master point for this point, it would give point "C", where
> correct point would be "A" as point
> "c" is far away based on polygon distribution.
>
> I would really appreciate any pointers or suggestions for the problem.
>
> Best Regards
>
> Prashant
>
>
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--
Dan Stowell
Postdoctoral Research Assistant
Centre for Digital Music
Queen Mary, University of London
Mile End Road, London E1 4NS
http://www.elec.qmul.ac.uk/digitalmusic/people/dans.htm
http://www.mcld.co.uk/
```