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cassini93 post(s)
#05-Aug-19 18:28

Good evening everyone,

I would like to measure the distance that separates a cloud of point to a landmark located more or less near.

It seems to me that this subject has been treated several times but I can not find any trace on the forum.

I enclose a file to illustrate the subject, thanking you for any advice you may have.

good day end to the workers

Dimitri


5,620 post(s)
#05-Aug-19 18:56

In 9, use the GeomDistance SQL function. That measures the distance between two geoms. First, convert the cloud of points to a single multipoint, so the whole cloud is one geom. Next, use that function between that geom and the geom for the landmark point.

By the way, there was no file attached.

cassini93 post(s)
#08-Aug-19 09:07

Hello Dimitri,

unfortunately, I have not yet had the chance to upgrade to the latest version and I still work with Manifold 8.

I should update by September, but I'm taking advice if i can do it with the current version.

Here is the file in Manifold8, that i forgot to attach to my last post.

Thank you for the answer.

Attachments:
Distance topoint.map

Dimitri


5,620 post(s)
#08-Aug-19 09:38

I think the function in 8 is called Distance. I've switched gears to 9, so I can't help you with the 8 query, but no doubt there are people here who can.

oeaulong

236 post(s)
#08-Aug-19 17:31

A couple of questions to clarify my confusion..

What units of measurement are you using? Your .map file is in Lat/Long so would be in degrees, is this correct?

What specifically do you mean by "distance to a cloud of points"? Are you looking for distances from your landmark to each individual point? A network diagram then distances along each closest point?

Or, are you looking for the cloud as an individual object then the distance to the centroid of the object? If this is the case, then your .map file has the landmark central to the cloud.

ed: attached is a modified map of what *I think* you are meaning.

Attachments:
Distance topoint_mod.map

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