Questions tagged [nearest]
Questions on the usage of Nearest and creating a custom distance function for it; also on NearestNeighborGraph, RegionNearest, GeoNearest and related concepts.
54
questions
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144
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Fastest Way to Find nearest indices between two sorted lists
I have a sorted list of floats of length n and an n x n list of lists, where each nested ...
- 229
1
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1
answer
46
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Issue with using complexplot with Nearest
I have been trying to create a certain fractal with Mathematica but the main issue is that if I try and do something like
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2
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2
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137
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Finding the minimal distance of a point from an interpolated function
I have an interpolating parametric function (solution of a set of differential equations) and I have an external point. I would like to find the minimal distance between this point and the ...
- 403
1
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0
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74
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1
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1
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139
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Finding the smallest bounding simplex [closed]
I would like to find the subset of points from a set of d-dimensional points that defines the smallest bounding simplex around a given point. For example, given a set of 3-dimensional points S1 and ...
0
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1
answer
59
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How to obtain the grouped separate line curves from the disorder data?
The sample point data and codes are listed as following. The point-image tells us that the data can be divided into nine groups. However, why are they divided into two groups by ...
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3
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1
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124
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How do I create an STL file from nearest neighbour graph edges?
I'm trying to figure out to deal with (and design) .stl files within Mathematica.
As an example, I would like to generate a FCC lattice without the atoms (but connecting all nearest neighbours), and ...
- 465
7
votes
2
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221
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Why does Nearest not return both equally distant values?
Define the following three vectors:
a = {0., 0., 0.};
b = {-0.5`, 0.4330127018922193`, 0.25`};
c = {-0.5`, 0.`, 0.`};
Note that the distance from a to c is the ...
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1
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191
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How to find the shortest distance between two regions?
I need to find the shortest distance between the two regions and the two points of the shortest distance, but the following code cannot achieve this requirement:
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8
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1
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215
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Furthest point from nearby objects, packing a sphere on a region interior
Suppose I have a boundary $\partial\Omega$ of a region $\Omega\subset \mathbb{R}^3$ and within this are some compact objects $B_i\subset\Omega$. They could be points, lines, polygons, complex 3D ...
- 22k
2
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1
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92
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How to get a NearestNeighborGraph[] for a given radius with periodic boundaries?
I'm wondering if there's a way to use NearestNeighborGraph with periodic boundaries, using all nearest neighbors within some radius.
I am aware of similar custom ...
- 1,583
3
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2
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277
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Position of Nearest in sublist
I want to get the position of nearest value or the position of the value in a certain range.
When I have the list, such as
...
- 107
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0
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83
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Nearest Region of a Point-cloud
For a given examplary set of points p(2D) with known NearestFunction nf
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- 43.1k
9
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2
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501
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Drawing lines between nearest neighbor points
I am reading a file with 4 columns (índex and 3 coordinates) and I want to plot spheres at these positions:
...
6
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1
answer
64
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NearestTo causes a kernel crash when applied to a list of SparseArrays [closed]
Nearest and NearestTo cause a kernel crash on Mathematica 12.0.0 for Mac OS X. (running on OS X 10.11.6) when operating on a list of SparseArray vectors.
Here's my minimal breaking example:
...
- 2,420
2
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2
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108
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How to Create an Efficient Step Function from Data
I have list of rules from where a DateListStepPlot can be created to visualize the problem:
...
- 1,657
3
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2
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607
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Find the smallest and largest distance between two points distributed in 3D space
Suppose I have some 3D points, e.g. {{0, 0, 1}, {0, 0, 1.3}, {0, 1, 0}, {1.2, 0, 0}}. Now I want to find the smallest and largest distance between two points.
A ...
- 902
10
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2
answers
249
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Efficient multicolor search
I'm hoping someone can help me improve the following fun code-snippet, which takes a target color and searches through a set of images to find the ones that most closely match:
...
- 30.8k
0
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0
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32
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Ordering a list of elements as shortest euclidean distance between two points [duplicate]
I've got a list of points:
...
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2
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388
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Speeding up Nearest with multiple distance thresholds
Consider the following example of using Nearest:
...
- 231k
14
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3
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457
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Is there a built-in function I can use to measure the similarity of two trees?
This is a higher level question, and I don't expect a full answer, but maybe a nudge in the right direction would help, or maybe there is a built in Mathematica function that does something very ...
- 1,407
4
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2
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275
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How to use Nearest as a lookup function?
I have data1 and a target point targetPts, and want to find the closest point from the data. As you can see from below, the 29th ...
- 3,419
8
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3
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269
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How to connect all points in a graph generated by a set of given vertexes?
I am trying to construct a tree by looking at the nearest neighbors (or just approximately nearest for higher efficient) of a set of given vertexes. I first try this:-
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- 3,419
1
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0
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147
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Estimating Lyapunov exponent from a time series problem [duplicate]
I am trying to use this code for estimating L.e.:
...
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2
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251
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Find the element in a list of triples which has z-coordinate nearest a specified value
Here is my list coordinate {x,y,z}
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- 215
1
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2
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1k
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Finding the x-value corresponding to a y-value found using Nearest [closed]
I have a large 2d array of infinite precision named "data" of x values and y values. I am using Nearest to find the y-value closest to a specified number, say 0....
- 11
3
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0
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140
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Getting Distances from Nearest Function [closed]
I am fairly new to mathematica. I am trying to find a way to mock python's KDTree.query function in mathematica. Basically I have 9 vectors (each length two). I want to know the three closest vectors ...
- 31
4
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4
answers
252
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Forming tracks of coordinates depending on distance
I have a list that consists of certain number of coordinates sub-lists (here 8).
(The following data are only an example to describe my problem.)
...
- 11.5k
1
vote
1
answer
153
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Define a 3D surface for input in Region function
I am looking for the shortest distance from a 3D surface to a random point, and also for the exact point on the surface.
These are the definitions and visualization.
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5
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1
answer
403
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Nearest non-collinear/non-coplanar points
This is a long post. Most of it is just an introduction so the question itself is understandable. The question is in bold. Just skip to it if you want to hear the point. Everything below the question ...
- 2,284
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1
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How can I get get index and distance in Nearest functions in Low Version [closed]
Nearest[{"I'm", "sorry", "Dave"} -> All, "David"]
{<|"Element" -> "Dave", "Index" -> 3, "Distance" -> 2|>}
However, in a WolframScript.wl file, ...
- 8,429
4
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1
answer
428
views
Opposite of Nearest?
There is an useful function Nearest in Mathematica, which finds the element in the aggregate given as its 1st argument that is nearest to its 2nd argument. It is ...
- 297
1
vote
0
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115
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A question for Nearest [closed]
Assume that I want to get nearest 10 points of a thousand random points in a given area to original point in three-dimensional coordinate system.
Does anyone know how the ...
- 113
1
vote
2
answers
240
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Using Nearest with periodic boundary conditions of a list
Take the list
e = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
I want to get the nearest points but with a wraparound condition. So lets say I want to find the 5 nearest ...
- 567
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votes
1
answer
699
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How to rapidly find the nearest pairs of points in different clusters
Background
For speed up this question or this question,I have such need.
Current try:
Suppose I have $3$ clusters of points:
...
- 25.3k
6
votes
2
answers
266
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How to find the index of a facet of a boundary mesh region closest to a given point?
Using the RegionNearest[] function, it is possible to calculate the point, $p_{mesh}$, on a mesh region that is nearest to some input point, $p_{input}$. My ...
- 3,783
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1
answer
970
views
Better way to use Nearest
I'm trying to write a snippet of code that, given an input value (value), checks a list of arbitrary length (data) for the ...
- 103
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2
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280
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Finding Nearest Element to a line in a 2 dimensional Array
I have a 2-dimensional list of data of $x$ and $y$ coordinates. I am looking for a way to get the element of the list which has the closest $y$ value to a given $y$ value. I tried using ...
- 258
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3
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293
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Question about Nearest [duplicate]
In the following example Nearest finds the nearest values between list1 and list2 and ...
- 11.5k
4
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3
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778
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Remove 2D points where nearest neighbor exceeds certain distance
I have the following 2D points:
...
- 11.5k
5
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3
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463
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Mean distance beween nearest 2 coordinates
I have as an example the following 2d-coordinates:
...
- 11.5k
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2
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Tracing 2d coordinates by using Nearest function
In 5 digital images I have determined the 2d coordinates of detected objects.
The resulting coordinate list can be downloaded from here: http://pastebin.com/7bE0CEJ5
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1
vote
3
answers
250
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Why won't DiscretizeRegion work with a custom distance function?
I am trying (in 10.0) to create a region from a list of data points. I have created myDistance to use as the boolean test for whether or not a point should be included in the region
...
- 352
4
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1
answer
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Draw lines between all neighbours
I have seen this question, but what I want is a bit different.
I have a set of data (blue points) and I would like to end up with something like this:
,
i.e. joining each site with all its (nearest)...
- 1,442
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1
answer
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precision and speed inefficiency issues of Nearest function with sqrt expression [closed]
Recently, Nearest has been attacked for many bugs. Some are already fixed.
I am going to show some issues when Nearest applied ...
- 16.6k
5
votes
2
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1k
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How to get Nearest lower value?
Nearestgives me the closest value to my reference, but what if I am always looking for the closest value, which is lower than my reference?
...
- 713
10
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1
answer
234
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Why does Nearest not support Sqrt?
Bug introduced in 10.0.2 and fixed in 10.3.0
Simple examples with two points
nf1=Nearest[{{0, 0}, {Sqrt[2], Sqrt[2]}}]
nf1[{0, 0}, {All, 2.1}]
gives
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15
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3
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792
views
Cannot get nearest neighbors from Nearest
Bug introduced in 10 and fixed in 10.3
There still persists the failure to return 30.72 (another bug according to Daniel Lichtblau but from the developer's point of view it may be a feature).
...
- 1,065
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3
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420
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Using an ellipse as a threshold for Nearest function
The Nearest function can receive as a threshold parameter a radius to look for elements inside that. From the documentation:
...
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