I have a matrix A and I compute the dissimilarity matrix using the downloaded function. H is the conjugate transpose operator (which is the ordinary transpose if a is real-valued). file began to complain that "??index=linspace (1,size (points,1),size (points,1)); is the strangest way I've seen of simply doing: Theme. 获取定价信息. Computes. how can I add a dot product as a distance function in pdist of matlab. pdist_oneLine. E=pdist2（X，Y-mean（X），'mahalanobis'，S）. Las funciones de distancia son: PDIST, PDIST2, Mahal, Forma Square, MdsCale, CMDSCALE. If so, the hypot function would work best. 这里 X 是 mx-by-n 维矩阵，Y 是 my-by-n 维矩阵，生成 mx-by-my 维距离矩阵 D。. pdist2 (P1,P2, 'cityblock'); But in my case, I want to use the columns of my. i. Para la generación de código, defina una función de punto de entrada que acepte las posiciones de los centroides de los grupos y el nuevo conjunto de datos, y devuelva el índice del grupo más cercano. Rows of X and Y correspond to observations, and columns correspond to variables. I use the pdist2 function to calculate the the distance between the points stored in matricies. MATLAB 距离函数及用法. example. between each pair of observations in the MX-by-N data matrix X and. 4 Answers. There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. y = squareform (Z)Dear Gentlemen i face problem when i use pdist2 function of hamming distance between two binary images in same size, the output result is an array not a percentage value, where i want to use hamming distance to calculate the percentage difference between two binary images:Hi, please I want to calculate the distance. Pdist2 inside for. mat file and we'll show you how you can use pdist2() to find close points. The loop is faster, because Matlab have to access the three used arrays X, Y and d6 locally only. 0 Comments. A= [0 0, -5. m","contentType":"file. From the documentation: Returns a condensed distance matrix Y. If instead there is an efficient algorithm for what pdist2 does, you can research it and possibly write your own variation that. To do that you'd have to use the algorithm I outlined. % Learning toolbox. 1 Answer. One immediate difference between the two is that mahal subtracts the sample mean of X from each point in Y before computing distances. Y = pdist (X, 'canberra') Computes the Canberra distance between the points. BUG (??) :pdist x dist x pdist2. The Age values are in years,. Sorted by: 1. Copy. example. Goncalves. Viewed 434 times 0 I'm trying to compare the histogram of an image (hsv) with a cell array that contains the histograms of other images in order to find out the closest matches. Later on, after some calculations with the newly transformed matrix, I need to convert it back to the original size in order to display the image. Hi everybody, i have two 3D matrix A and B with different lengths. D = pdist2 (X,Y,@CalcDist) function D2=CalcDist (ZI,ZJ) % calculation of distance. pdist2 calculates the distances between points in two vectors and returns a vector which. ,an｝，将它们按大小顺序排列，取中间的那个值作为滤波器的输出。 @Lukas Gaßmann Start your own question with your EEG data attached in a . See inline comments for details (some of which are important). 78874218621840] Your third party file c:\toolbox\classify\pdist2. 可以这样理解 D 的生成：首先生成一个 X 的距离方阵，由于该方阵是对称的，且对角线上的元素为0，所以取此方阵的下三角元素. particle. 0. The equivalent. example. . But in your case the matrix has only rank D = PDIST2 (X,Y,DISTANCE, 'Largest',K) returns the K largest pairwise distances sorted in descending order. for low dimensional points (3 in this example) it should be more efficient to. ind = dsearchn (tmpref, tmptar); But knnsearch is tested ⵜ to be faster than dsearchn in this case. It will not be the longest perpendicular distance along the centerline. This function computes the M-by-N distance matrix D where D(i,j) is the distance between. %. you also define a custom distance function. 使用四个预处理器指令来控制条件编译：. It computes the distances between rows of X. {"payload":{"allShortcutsEnabled":false,"fileTree":{"":{"items":[{"name":"README. squareform returns a symmetric matrix where Z (i,j) corresponds to the pairwise distance between observations i and j. Load the patients data set. Pass a single point for each of the first two arguments to pdist2 and the result will be a single distance. % Learning toolbox. The latest upgrades to your MATLAB and Simulink products – with releases twice a year packed with new features and performance improvements. The cryptographic operation under attack is the implementation of AES-256 RSM. [D,I] = pdist2 (X,Y,distance,‘Smallest’,K) 生成 K-by-my 维矩阵 D 和同维矩阵 I，其中D的每列是原距离矩阵中最小的元素，按从小到大排列，I 中对应的列即为其索引号. Copy. chapter 5. distance. Computes the Euclidean distance between rows of two matrices. . I know the distance(lat1,lon1,lat2,lon2) command is the suitable for this but I want to use pdist2 command. Learn more about matrix manipulation, distance, pdist2, matlab function, indexing, matrix, arrays MATLAB I was wondering if there is a built in matlab fucntion that calculates the distance between two arrays that don't have the. example. D = pdist2 (X,Y) returns a matrix D containing the Euclidean distances. figure. distances (i,j) = pdist2 (blobMeasurements (i). A pixel is an element of a matrix that represents something (like reflectance) of a certain scene. 3 Answers. The points are created randomly, lets take 5 points. Your third party file c: oolboxclassifypdist2. Read case names from an ascii file. Technical support available in 10 languages via telephone, email, and the web. function Distance = euclidean (x,y) % This function replaces the function pdist2 available only at the Machine. This norm is also. pdist2 is optimized to return the distance from each of the points in the first argument to each of the points in the second argument, so if you only want one distance then only pass a single point to each. The Canberra distance between two points u and v is. caseread. Use pdist2 to find the distance between a set of data and query points. n = norm (A) returns the 2 -norm of symbolic matrix A . If you have the Statistics Toolbox: Response = ~(pdist2(index, A)); or: Response = ~(pdist2(index, A, 'hamming')); This works because pdist2 computes the distance between each pair of rows. 1. % n = norm (v) returns the Euclidean norm of vector v. The weights for each value in u and v. pdist supports various distance metrics: Euclidean distance, standardized Euclidean distance, Mahalanobis distance, city block distance, Minkowski distance, Chebychev distance, cosine distance, correlation distance, Hamming distance, Jaccard distance, and Spearman. Contribute to guy531/keystone development by creating an account on GitHub. 看看这是否会给你带来与. . In Matlab there exists the pdist2 command. for i=1:m. . end. 49836 0. pdist2 Pairwise distance between two sets of observations. squareform returns a symmetric matrix where Z (i,j) corresponds to the pairwise distance between observations i and j. Please show us how you are storing the line data, a relevant sample of code etc to make your problem clearer. sir is there any function to reduce row size. Ignore that code (I'll delete it) and use this instead: timeStamps = rand (numPoints1, 1) % Sample data. It computes the distances between rows of X. % Autor: Ana C. pdist2 Pairwise distance between two sets of observations. I know the distance(lat1,lon1,lat2,lon2) command is the suitable for this but I. Share. D = pdist2 (X,Y,Distance,DistParameter) returns the distance using the metric specified by Distance and DistParameter. For example, you can find the distance between observations 2 and 3. D = PDIST2(X,Y) returns a matrix D containing the Euclidean distances between each pair of observations in the MX-by-N data matrix X and MY-by-N data matrix Y. pdist2 Pairwise distance between two sets of observations. squareform (a. The. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. If a is m x r and b is n x r then. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. e. Try something like E = pdist2 (X,Y-mean (X),'mahalanobis',S); to see if that gives you the same results as mahal. Now, it is confirmed that I do not have a license. The result comes with so much noise and i cannot see the result of length measurement. Sorry - that's what I get for tossing something off the top of my head and not actually testing it. For a 2D input case, you can define a kernel function that takes two inputs and returns a scalar value. MY-by-N data matrix Y. Distance MetricsX의 관측값 i 또는 Y의 관측값 j가 NaN 값을 포함하는 경우, 함수 pdist2는 i와 j 간의 쌍별(Pairwise) 거리로 NaN을 반환합니다. % ZJ is an m2-by-n matrix containing multiple observations. D = pdist2 (X,Y,Distance) returns the distance between each pair of observations in X and Y using the metric specified by Distance. I want to measure the distance in every point in X to every point in Y where each point in X coresponds (maps) to one point in Y, regardless of the specific order the points initially started out in. We can use it as follows to perform the same computation as above: import numpy as np import numexpr as ne X_norm = np. If you want the cosine, use 1-pdist2 (matrix1,matrix2,'cosine'). m should be stored in the directory identified below. % n = norm (v) returns the Euclidean norm of vector v. 这些特征描述了一个人的基本特性，通过身高，体重，我们想象一. Answers (1) Two possibilities come to mind, one being knnsearch (link), and the other being pdist2 (link). A distance function must be of the form . Note. >>> n_new_companies, n_new,. Fowzi barznji on 16 Mar 2020. The Canberra distance between two points u and v is. RMSFramesMat; EucDist = pdist2 (neutralRMSdata, FileRMSdata, 'hamming');Each row of both matrices identifies a point in 2D space. I am getting the following error: Theme. Quick Start. % ZJ is an m2-by-n matrix containing multiple observations. m. example. function D = pdist2( X, Y, metric ) DESCRIPTION . pdist (Statistics Toolbox) Y = pdist (X,' Y = pdist (X,distfun,p1,p2,. Copy. If you are getting the matrices as an output from some code, I strongly recommend you directly store them. Utilice kmeans para crear grupos en MATLAB® y utilice pdist2 en el código generado para asignar nuevos datos a grupos existentes. There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. I mean a 1-to-1 mapping of points. {"payload":{"allShortcutsEnabled":false,"fileTree":{"":{"items":[{"name":"FastMICE_ConsensusFunction. is there an alternative to pdist2 that calculates the distance between a matrices with different column numbers. My problem is taking those distances out of the matrix and finding the smallest combined distance for each unique set of X to Y measurements. Equal rows have distance 0. Categorizing query points based on their distance to points in a training data set can be a simple yet effective way of classifying new points. pl. Matlab - Not getting the expected result. Given the matrix mx2 and the matrix nx2, each row of matrices represents a 2d point. Hay una función correspondiente en Matlab, que es conveniente para llamar al cálculo. de 2022 I'm trying to use the pdist2 function and keep getting this error: "??? Undefined function or method 'pdist2'. Anyway, when you have a built-in function in Matlab, it will almost always outperform hardcoded ones so just go with pdist2. 2种计算方式，一种直接利用pdist计算，另一种. However, I use this matrix in a loop like this : for i:1:n find (Distance (i,:) <= epsilon);. pdist2. What i want to do is to write a code, that does not involve loops and pdist2, as fast as possible, that tells me the indices of the row of both A and B such that the distance. md","path":"README. cholesky# linalg. I don't think it is any faster computing that with hand-written MATLAB code. Documentation, examples, videos, and other support resources for MathWorks products including MATLAB and Simulink. pdist(X, metric='euclidean', *, out=None, **kwargs) [source] #. In the case of the manual method you are using the i index in both of them. Sign in to your MathWorks Account or create a new one. For a dataset made up of. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. pydist2 is a python library that provides a set of methods for calculating distances between observations. One matrix has 2 sets of coordinates. pdist2 Pairwise distance between two sets of observations. If you want to order the points from B by their distance to the r th point in A then you can sort the r th row of the pairwise distance matrix. Everything compiles fine without errors etc. The code should (hopefully) be easily readable since it has been well commented, with report for background. pdist2 calculates the distances between observations in two vectors with one of the following methods: manhattan: The L1 distance between two vectors P and Q is defined. The Hamming distance between two vectors is the percentage of the vector components that differ. For a dataset made up of. 2. The primary class definition contains a signature for the function. D = pdist2 (X,Y) returns a matrix D containing the Euclidean distances. Select a Web Site. pdist2 supports various distance metrics: Euclidean distance, standardized Euclidean distance, Mahalanobis distance, city block distance, Minkowski distance, Chebychev distance, cosine distance, correlation distance,. To check the existence of a global variable: if 'myVar' in globals (): # myVar exists. the program has this error: Struct contents reference from a non-struct array object. D = pdist2 (X,Y,Distance,DistParameter,'Largest',K) computes the distance using the metric specified by Distance and DistParameter and returns the K largest pairwise distances in descending order. PDIST2 introducido principalmente, otros pueden. Dev-iL Dev-iL. figure. We bring some examples of bigram association calculations from Manning and Schutze’s SNLP, 2nd Ed. cdist (array, axis=0) function calculates the distance between each pair of the two collections of inputs. Currently avaliable codes in FEX are also insufficient as they can only compute (squared. ; Home automation: To maintain security, especially in a home that is. The dot of the i will have a lower y value of its centroid than the body of the i. You will use the clustergram function to perform hierarchical clustering and generate a heat map and dendrogram of the data. To save memory on the device, you can separate training and prediction by using kmeans and pdist2, respectively. MY-by-N data matrix Y. I'm trying to use the pdist2 function and keep getting this error: "??? Undefined function or method 'pdist2' for input arguments of type 'double'" The 'double' part changes depending on what data. so please let me know difference between columns and bins and how it affects histogram?data = gpuArray (data); mu = gpuArray (mu); dist = pdist2 (data, mu, 'euclidean') Without gpuArrays, there is no problem with using the 2 functions. Copy. Description. Currently avaliable codes in FEX are also insufficient as they can only compute (squared. In this workflow, you must pass training data, which can be of considerable size. – Nicky Mattsson. % accept a matrix ZJ with an arbitrary number of observations. In Matlab there exists the pdist2 command. which -all pdist will list all the pdist MATLAB files in your MATLAB path. Compute the Cosine distance between 1-D arrays. Sign in to comment. D = pdist2 (X,Y,Distance) returns the distance between each pair of observations in X and Y using the metric specified by Distance. index = 1:size (points, 1); In some places you use length (points). pydist2 is a python library that provides a set of methods for calculating distances between observations. % n = norm (v) returns the Euclidean norm of vector v. I have two matrices X and Y. between each pair of observations in the MX-by-N data matrix X and. This would be done automatically by the compiler if pdist2 were not a template function:. 0 installed and run with flatpak, I can install the statistics package from Octave Forge, and the results are the same as others have shown here: >> D = pdist2 (X, Y) D =. This way, you offload the bother of vectorization to the people who wrote MATLAB/Octave (and they have done a pretty good job of it) X = rand (10,3); Y = rand (5,3); D = pdist2 (X, Y); D is now a 10x5 matrix where the i, j th. Learn more about latitude, longitude, closest value, grid, dipole grid, great circle distance. In human motion analysis, a commond need is the computation of the distance between defferent point sets. plot (xi,t1,'r',xi,t2,'b'); legend ( {'Manual','Pdist2'}) Which probably suggests that any differences in time between pdist2 and manual calculation are negligible and more dependent on the current background state of the CPU. % pairwise mahalanobis distance with pdist2() E = pdist2(X,Y,'mahalanobis',S); % outputs an 50*60 matrix with each ij-th element the pairwise distance between element X(i,:) and Y(j,:) based on the covariance matrix of X: nancov(X) %{ so this is harder to interpret than mahal(), as elements of Y are not just compared to the "mahalanobis-centroid" based on X, % but to each individual element of. def test (trainY, testY, traingnd, testgnd, radius=2): # make sure trangnd and testgnd are flattened testgnd = testgnd. D = pdist2(X,Y); 用法：设X为一个M行N列的矩阵，Y为一个P行Q列的矩阵，则函数的返回值D为一个M行P列的矩阵。 pdist2计算X中任意一个行向量与Y中任意一个行向量的距离，默认采用欧氏距离公式。 dist = pdist2(d,centroids,distance); % distance between all data points and centroids I'd like to mention that I used matlab in system with windows 8 and following configuration : 中的每个点减去. 1 Enlazar Traducir Comentada: Ana Gonçalves el 16 de Feb. So, do you know how to make the calcul inside the. You can also use the Image Labeler to train a custom classifier to use with this System object. . In order to visualize the final result just add to Gunther's code the following lines: row=data (:,1); col=data (:,2); figure scatter (row,col,'r'); hold on line (row (result),col (result)); The following code shows the same algorithm but for a 3D. % Learning toolbox. Warning: Converting input data to single. Copy. 93847 0. Learn more about unrecognized fuction or variable xpydist2 tutorial. linalg. Copy. %. There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. I think it is not correct. It will not be the longest perpendicular distance along the centerline. I'm trying to calculate Haversine distance but I don't know how to apply the funtion in this case. You can rate examples to help us improve the quality of examples. md","contentType":"file"},{"name":"TKDE_Ultra-Scalable Spectral. Let X be an MxP matrix representing m points in P-dimensional space and Y be an NxP matrix representing another set of points in the same space. Given X = randu(3, 2), Y = randu(3, 2), where each row stores an observation (x, y). Any help. m. 9448. Learn more about histogram comparison, image comparison, image segmentation, distance comparison, chi-square Image Processing Toolbox hi, I am having two Images I wanted compare these two Images by histograms I have read about pdist that provides 'chisq' but i think the way i am doing is not correct. 相同的结果，我想有两种不同的方法来计算两组数据之间的马氏距离，就像你上面解释的那样： 1） 将样本集中的每个数据点与. NaN NaN NaN NaN 1 2 2 NaN 3 1. Parameters : array: Input array or object having the elements to calculate the distance between each pair of the two collections of inputs. Then sum() is fed with the complete result, and throws the result again to the RAM. For example, you can find the distance between observations 2 and 3. Share. In Matlab, the D = pdist(X, Y) function computes pairwise distances between the two sets of observations X and Y. The pdist2 function is overkill for what you want to do. 52181708330649 5. Different behaviour for pdist and pdist2. Input array. OK. spatial. n = norm (v,p) returns the p -norm of symbolic vector v. Copy. end. clear A = rand (132,6); % input matrix diss_mat = pdist (A,'@kullback_leibler_divergence'); % calculate the. m. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. 0. sir is there any function to reduce row size. D = pdist2(X,Y,@distfun) the custom distance function has to have this header. % Autor: Ana C. I would like to use the command pdist2 in order to compute distance between two geographical coordinates. k2 = dsn (single (x),single (xi)); but this is still not enough for me. distance. 代わりにpdist2という関数があります。 こちらは、2つのベクトルの距離を計算しますが、プロパティで距離のタイプを選ぶことができてその中にマハラノビス距離があります。scipy. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. to see if you have multiple pdist2, and use pathtool to make sure that the Statistics Toolbox one is earlier on your search path. In any case you could use this: function MD = my_MahalanobisDistance (X, Y) [nX, mX]. pdist2() is going to return a 2D array that is number of rows in color_table by number of rows in the reshape()For a proyect I want to use pdist2 (Pairwise distance between two sets of observations) but I need an specific function. It computes the distances between rows of X. What is the computacional complexity in asymptotic notation, O(n) , for the function "pdist2" ? 0 Comments. Pair distribution functions were calculated using Matlab’s ‘pdist2’. These measures are useful to determine whether the coocurrence of two random events is meaningful. D = pdist2(X,Y) returns a matrix D containing the Euclidean distances between each pair of observations in the MX-by-N data matrix X and function Distance = euclidean (x,y) % This function replaces the function pdist2 available only at the Machine. The following example shows the WDATP configuration service provider in tree format as used by the Open Mobile Alliance (OMA). pydist2 is a python library that provides a set of methods for calculating distances between observations. MY-by-N data matrix Y. Pdist2 inside for. Unlike pdist, pdist2 takes two sets of data X = { x i } i = 1 m and Y = { y j } j = 1 m and compute m n number of pairwise distances for all i and j. Show -1 older comments Hide -1 older comments. % Learning toolbox. I was wondering if there is a built in matlab. m is interfering with use of the pdist2 from the Statistics toolbox. I need to build a for loop to calculate the pdist2 between the first row of A and all the rows of B, the second row of A. With Octave 5. In the case of a symmetric matrix this means that all eigenvalues must be positive. But here's one possible cause: When you call pdist2 with a custom distance function, it should meet the following condition:. The builtin function `pdist2` could be helpful, but it is inefficient for multiple timeframes data. You need to wrap the distance function, like I demonstrated in the following example with the Levensthein distance. B = [38. y = squareform (Z)Pairwise distances between observations, specified as a numeric row vector that is the output of pdist, numeric square matrix that is the output of pdist2, logical row vector, or logical square matrix. If you didn't then the result in in pixels and you'll have to multiply those distances by the spatial calibration factor. pcshow (ptCloud. 判别分析时，通常涉及到计算两个样本之间的距离，多元统计学理论中有多种距离计算公式。MATLAB中已有对应函数，可方便直接调用计算。距离函数有：pdist, pdist2, mahal, squareform, mdscale, cmdscale 主要介绍pdist2 ,其它可参考matlab help D = pdist2(X,Y)D = pdist2(X,Y,distance)D = pdist. Along the diagonal are the matching row cases. To check the existence of a local variable: if 'myVar' in locals (): # myVar exists. The attacks. I thought it will comes up with skeleton line and show the length beneath of the line. I need to find the minimum distance between the two bones, I am attaching two. . The most efficient pairwise distance computation. License: GNU General Public License v3 (GPLv3) Author: Benjamin Paassen Tags levenshtein-distance, dynamic-time-warping, sequence-edit-distance, sequence-alignment, tree-edit-distance, algebraic-dynamic-programmingmatlab中自带的计算距离矩阵的函数有两个pdist和pdist2。前者计算一个向量自身的距离矩阵，后者计算两个向量之间的距离矩阵。基本调用形式如下： D=pdist(X) D=pdist2(X,Y) 这两个函数都提供多种距离度量形式，非常方便，还可以调用自己编写的距离. where u ⋅ v is the dot product of u and v. Rows of X and Y correspond to observations, and columns correspond to variables. Thank you! I tried this, and it didn't quite work for me because I didn't make. 23. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. 2. Returns: cityblock double. 3 Comments. The biggest distance using pdist2() will be from one end of the line to the opposite end of the other line. D = pdist2 (X,Y,Distance,DistParameter) returns the distance using the metric specified by Distance and DistParameter. After reading through the documentation, it is a very versatile tool. . y = squareform (Z)pdist2 は、Y 内の各観測値について X 内の観測値すべてに対する距離値を計算して比較することにより、最小の 2 つの距離を求めます。 そして、D の各列に格納されている距離を昇順で並べ替えます。I には、D 内の距離に対応する X 内の観測値のインデックスが格納さ. matlab use my own distance function for pdist. pl)Homer contains a useful, all-in-one program for performing peak annotation called annotatePeaks. 2. Annotating Regions in the Genome (annotatePeaks. I've tried applying the funtion pdist2 with the added argument angdiff but I get the. A lazy way to do this is addpath (genpath (yalmiprootdirectory)) If you want to be even lazier, simply run the following code in the directory where you want to install YALMIP. However, manually defining the cell array is a limitation here. The most efficient pairwise distance computation. 比如说我们描述一个人，可以使用的特征很多，身高，体重，性别等等，这些特征往往都会有相应的值，身高 (180 cm)，体重 (70 kg)，性别 (男，女)。. Then I call the "load_training_data" method of NeuralNetworkSolution, in the "run" method of ConsoleApplication, with the correct number of arguments. [D,I] = pdist2(P, G, 'euclidian', 'Smallest', 1); Where G is the grid and P is your m-by-2 array of points to test. MATLAB's custom distance function example. Return the Cholesky decomposition, L * L. pdist1 and pdist2 The library can compute distances between pair of observations in one vector using pdist1, and distances between pair of observations in two vectors using pdist2. 59289 0. An m A by n array of m A original observations in an n -dimensional space. 0. * t at first and throws it from the cache to the slow RAM. > In pdist2 (line 253) In ExhaustiveSearcher/knnsearch (line 235) In knnsearch (line 154) In internal. Would you help correcting my. Pass Z to the squareform function to reproduce the output of the pdist function. kmeans를 사용하여 MATLAB®에서 군집을 생성하고 생성된 코드에서 pdist2를 사용하여 기존 군집에 새 데이터를 할당합니다. Y = cdist(XA, XB, 'hamming'). In human motion analysis, a commond need is the computation of the distance between defferent point sets. Nov 8, 2013 at 9:26. It computes the pairwise. Saltar al contenido. squareform returns a symmetric matrix where Z (i,j) corresponds to the pairwise distance between observations i and j. D = PDIST2(X,Y) returns a matrix D containing the Euclidean distances between each pair of observations in the MX-by-N data matrix X and MY-by-N data matrix Y. Compute distance between each pair of the two collections of inputs. Say a gaussian process regression take with predictor X in 2D, i. This diff based approach could be more efficient - %// Concatenate A and B AB = sortrows([A B]. % requiring few or no loops.