I want you to clear one thing as I noticed now though I changed bins to 59 but still number of columns in color image remains 1024 only I displayed it on command prompt. Sorry - that's what I get for tossing something off the top of my head and not actually testing it. and the reshape() gives a 2D array. 7. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. Parameters : array: Input array or object having the elements to calculate the distance between each pair of the two collections of inputs. I simply call the command pdist2(M,N). It will give you the best groups in aggregate that are farthest away though it's possible some from group1 are closer to some points in group2 that you'd prefer. Matlab-pdist2函数用法. squareform returns a symmetric matrix where Z (i,j) corresponds to the pairwise distance between observations i and j. 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. . NaN NaN NaN NaN 1 2 2 NaN 3 1. 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. Share. D = pdist2 (X,Y) returns a matrix D containing the Euclidean distances. example. Data can be combined with base map. . For Part I, we are provided with the corresponding 3d and 2d. Rows of X and Y correspond to observations, and columns correspond to variables. D = pdist (X) 计算 X 中各对行向量的相互距离 (X是一个m-by-n的矩阵). There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. y = squareform (Z)That's a no-no for 'pdist2'. m. Sorted by: 1. Share. Because symbolic variables are assumed to be complex by default, the norm can contain unresolved calls to conj and abs. In the meantime, try the code below and if it helps you click on the Vote button near my top answer. D = pdist2 ( X,Y, Distance) 中的每一对观测之间的距离。. It computes the distances between rows of X. spatial. Show us your code so we can confirm it. A distance metric is a function that defines a distance between two observations. Connect and share knowledge within a single location that is structured and easy to search. 2. Learn more about TeamsAccepted Answer: Star Strider. 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. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. between each pair of observations in the MX-by-N data matrix X and. Sign in to comment. 这里 D 要特别注意，D 是一个长为m (m–1)/2的行向量. normal,'jaccard'); end. The attacks. You can use various metrics to determine the distance, described next. example. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. % Autor: Ana C. I've found the right answer (by Gunther Struyf): Sort Coordinates Points in Matlab. pdist2 Pairwise distance between two sets of observations. Every time I want to use pdist2, I get the following error: Undefined function 'pdist2mex' for input arguments of type 'double'. 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. 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. Both represent a number of positions in 3D-space. The distance between each sample in A and each sample in B can be calculated as follows: First, define a matrix D of size 75x50, s. Theme. The result comes with so much noise and i cannot see the result of length measurement. Nov 8, 2013 at 9:26. The Hamming distance between two vectors is the percentage of the vector components that differ. m or remove that directory from your MATLAB path. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. D = pdist2 (X,Y) returns a matrix D containing the Euclidean distances. ') %//' %// Use DIFF to get a logical array of repetitions and %// use. % Get the value from column 1. sir is there any function to reduce row size. % Isolate data that are within a square around the circle. PDIST2 Pairwise distance between two sets of observations. You can use the pdist2 MATLAB / Octave function to calculate pairwise distances between two sets of observations. You need to wrap the distance function, like I demonstrated in the following example with the Levensthein distance. % ZI is a 1-by-n vector containing a single observation. Modified 8 years, 5 months ago. Pdist2 inside for. Run this line of code which should open the directory where this function is stored and look for that function (for Windows) winopen (fullfile (matlabroot,'toolboxoptimoptim')) If the file exists, the path has somehow been removed. Return the Cholesky decomposition, L * L. Y = pdist (X, 'canberra') Computes the Canberra distance between the points. X 和 Y 使用 Distance. 52181708330649 5. Z (2,3) ans = 0. Two sets of matrix. In the meantime, try the code below and if it helps you click on the Vote button near my top answer. pdist (X): Euclidean distance between pairs of observations in X. The Canberra distance between two points u and v is. Different behaviour for pdist and pdist2. I'm having some trouble in calculating the Mahalanobis Distance between a pair of objects. 52181708330649 5. % Autor: Ana C. lat and border [i+1] > loc. E=pdist2（X，Y-mean（X），'mahalanobis'，S）. Function File: pdist2 (x, y, metric) Compute pairwise distance between two sets of vectors. To follow along with this guide, first, download a packaged release of Spark from the Spark website. The weights for each value in u and v. 0. Given the matrix mx2 and the matrix nx2, each row of matrices represents a 2d point. 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. t D (i,j) is contains the number of matches between the sample i in A and the sample j in B. 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. Well, pdist2 finds the 8 nearest neighbors of every point (x0,y0) and if any of the neighbors is at a distance of >1 than (x0,y0) is classified as belonging to the sparse region, and is discarded from the list. Jim Lehane on 4 Mar 2013. % ZJ is an m2-by-n matrix containing multiple observations. to see if you have multiple pdist2, and use pathtool to make sure that the Statistics Toolbox one is earlier on your search path. 0. ordfilt2函数 在MATLAB图像处理工具箱中提供的二维顺序统计量滤波函数。它的滤波概念是中值滤波的推广，中值滤波是对于给定的n个数值｛al ,a2,. Parameters: XAarray_like. Same thing can be done with pdist2() but you'd need the Statistics and Machine Learning Toolbox to use pdist2(). There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. how can I add a dot product as a distance function in pdist of matlab. The most efficient pairwise distance computation. Goncalves. Mapping Toolbox supports a complete workflow for managing geographic data. Create a matrix with three observations and two. Y = pdist (X, 'canberra') Computes the Canberra distance between the points. For a 2D input case, you can define a kernel function that takes two inputs and returns a scalar value. . It compares row 1 of A with row 1 of B (Z(1,1)), then row 1 of A with row 2 of B (Z(1,2) and Z(2,1)), etc. Ignore that code (I'll delete it) and use this instead: timeStamps = rand (numPoints1, 1) % Sample data. longitude. Copy. 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. Copy. D = pdist2 (X,Y,Distance,DistParameter) returns the distance using the metric specified by Distance and DistParameter. Find more on Graphics Object Programming in Help Center and File Exchange. Online and cloud offerings such as MATLAB Online, MATLAB Drive, and MATLAB Mobile. #elif ：关闭前面的条件编译，并基于是否定义了指定的符号打开一个新的条件编译。. You can use one of the following methods for your utility: norm (): distance between two points as the norm of the difference between the vector elements. I would like to use the command pdist2 in order to compute distance between two geographical coordinates. Distance MetricsX의 관측값 i 또는 Y의 관측값 j가 NaN 값을 포함하는 경우, 함수 pdist2는 i와 j 간의 쌍별(Pairwise) 거리로 NaN을 반환합니다. Feature points (read corners) in images are points that invariant under view changes, zoom, lightening conditions etc. Input array. Hi everybody, i have two 3D matrix A and B with different lengths. BUG (??) :pdist x dist x pdist2. pydist2 is a python library that provides a set of methods for calculating distances between observations. The Canberra distance between two points u and v is. Theme Copy D = pdist2. Regards, Bhavya PDIST2 Pairwise distance between two sets of observations. Ultimately, the idea is that all the sparse. e. 1 Answer. I was told that by removing unnecessary for loops I can reduce the execution time. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. distance. 49140 0. dist = pdist2(trainingSet, testSet, 'euclidean') You can use this distance matrix to knn-classify your vectors as follows. This norm is also. axis: Axis along which to be computed. There are two main classes: pdist1 which calculates the pairwise distances between observations in one matrix and returns a distance matrix. Now I want to create a mxn matrix such that (i,j) element represents the distance from ith point of mx2 matrix to jth point of nx2 matrix. Sign in to answer this question. end. Add a comment. Si 'maximal', pdist2 intenta asignar suficiente memoria para una matriz intermedia entera cuyo tamaño es MX por MY, donde MX es el número de filas de los datos de entrada X y MY es el número de filas de los datos de entrada Y. tumor,F (i). The distance between each sample in A and each sample in B can be calculated as follows: First, define a matrix D of size 75x50, s. I simply call the command pdist2(M,N). m. 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. Learn more about pdist, dist, pdist2, not a bug, which -all Hi all, I always used pdist to calculate euclidian distance between two points, but suddenly my m. With Codie Lucas Wilbee, Joshua Murray, Frank C. This instuctional code demonstrates validation by posterior agreement for connectivity-based cortex parcellation of diffusion weighted imaging data. 따라서, D1(1,1), D1(1,2), D1(1,3)은 NaN 값입니다. Share. There will only be one smallest distance. Sir, actually the block[50 X 6] contains 'minutiae' information which contains the following data in columns [X, Y, CN, Theta, Flag, 1]and rows contains number of minutiae information on the dorsalhandvein. % n = norm (v) returns the Euclidean norm of vector v. I have a vector X which contain x and y value in column 1 and 2 respectively. % ZI is a 1-by-n vector containing a single observation. To find the distances between all possible pairs of pixels having gray levels 25 and 36 you need to first get the map of where those pixels are, then pass them into pdist2(). Let's say that the pixel to pixel spacing is 64 microns, and you want the distance between the 34th blob and the 78th blob. ), however at the end, it shows an important message. / (2*sigma^2)); K = [ (1:size. The point is that one of my main functions is to get the distance between 2 particles, and sometimes it returns 0 even if the particles are not that close. stats. Then, for the second set, at each iteration, it will set the (i,j) location to 0 and calculate. Note that the. cdist(XA, XB, metric='euclidean', *, out=None, **kwargs) [source] #. end. % ZJ is an m2-by-n matrix containing multiple observations. You can turn off this functionality with the "hold off" command. D = pdist2 (X,Y,Distance,DistParameter) returns the distance using the metric specified by Distance and DistParameter. You could save half the time by computing each pair only once. I know the distance(lat1,lon1,lat2,lon2) command is the suitable for this but I want to use pdist2 command. I make a calcul between each point : Distance = pdist2 (X,X); But sometimes I have a problem of memory. Let X be an m-by-p matrix representing m points in p-dimensional space and Y be an n-by-p matrix representing another set of points in the same space. Learn more about mahalanobis, mahal, pdist2, pairwise, difference, versus . It computes the distances between rows of X. Therefore, D1(1,1), D1(1,2), and D1(1,3) are NaN values. mahal() function. octave pdist (pairwise distance) 3. kmeans를 사용하여 MATLAB®에서 군집을 생성하고 생성된 코드에서 pdist2를 사용하여 기존 군집에 새 데이터를 할당합니다. Copy. distfun must. d(u, v) = max i | ui − vi |. 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. D = pdist2 (X,Y,@CalcDist) function D2=CalcDist (ZI,ZJ) % calculation of distance. example. for i=1:m. D = pdist2 (X,Y,Distance,DistParameter) returns the distance using the metric specified by Distance and DistParameter. Hello, I am using matlab 2019a and I am trying to sort points based on comparing the distance between them. Y = cdist(XA, XB, 'hamming'). I call this function from a different script HW3. t D (i,j) is contains the number of matches between the sample i in A and the sample j in B. pdist2 Pairwise distance between two sets of observations. Learn more about TeamsHow to save a value in a variable within a for loop without overwriting in MATLAB? for i = 1:length (X) %X is a CSV matrix 50x4 Y = X (i, :) % fetching each row of X dist = pdist2 (Y, X2, 'euclidean') %X2 is another matrix 100x4 sumOfdist = sum (dist); end; meanResult = mean (sum) sumOfdist will always be overwritten on each iteration and. Distance Metrics 장치의 메모리를 절약하기 위해 각각 kmeans와 pdist2를 사용하여 훈련과 예측을 분리할 수 있습니다. The Chebyshev distance between two n-vectors u and v is the maximum norm-1 distance between their respective elements. Email. Z (2,3) ans = 0. 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. end. You can import vector and raster data from a wide range of file formats and web map servers. 看看这是否会给你带来与. 82215. 2. cholesky (a) [source] # Cholesky decomposition. The loop is faster, because Matlab have to access the three used arrays X, Y and d6 locally only. It computes the distances. spatial. Show -1 older comments Hide -1 older comments. Hot Network Questionsisequal (k1,k2) nnz (k1-k2) The results k1 and k2 are identical (in some cases not, due to the internal numerical properties of pdist2). I want to compute the distance between two vectors by using Jaccard distance measure in matlab program. Compute distance between each pair of the two collections of inputs. I was wondering if there is a built in matlab. pdist and pdist2 can calculate the city block distance. Currently avaliable codes in FEX are also insufficient as they can only compute (squared. We bring some examples of bigram association calculations from Manning and Schutze’s SNLP, 2nd Ed. The City Block (Manhattan) distance between vectors u and v. You can use the pdist2 MATLAB / Octave function to calculate pairwise distances between two sets of observations. between each pair of observations in the MX-by-N data matrix X and. Assume I have two sets of matrix (A and B), inside each matrix contains few point coordinates, I want to find out point in B nearest to A and output a cell array C listed the nearest point pair coordinates accordingly and one cell array D register the unpaired spot, how should I do it?To be more specific, here is what I want. I know the distance(lat1,lon1,lat2,lon2) command is the suitable for this but I. 如果输入的是简洁的距离矩阵，将返回冗余矩阵；. BUT: The code shown here is 10-100 times faster, utilizing the. D = pdist2 (X,Y) returns a matrix D containing the Euclidean distances. It computes the distances between rows of X. D = pdist2 (X,Y,Distance,DistParameter) returns the distance using the metric specified by Distance and DistParameter. casewrite. Learn more about optimization Navigation Toolbox, Statistics and Machine Learning Toolbox. These are the top rated real world Python examples of utils. pdist2 computes the distances between observations in two matrices and also returns a distance matrix. 2 Answers. Equal rows have distance 0. With the knowledge of camera calibration and Epipolar Geometry, we can now improve the result we get from project 2 for keypoints matching. i. tic; d2 = pdist2 (p1,pn); t2 (p) = toc; end. 如果输入的是冗余的距离矩阵，将返回简洁的距离矩阵. You are using pdist2 with two equal input arguments ( X and Y are equal when you call kernel ). The equivalent. The function you pass to pdist must take . minDistance = 0. My code: function dist = distance (x1, y1, x2, y2) dist = abs ( (x1 - x2) + (y1 - y2)); It seems correct to me but i'd just like to make sure. You can use various metrics to determine the distance, described next. But pdist2 might have a lot of overhead. Compute pairwise distance between two sets of vectors. Use pdist2 to find the distance between a set of data and query points. pdist2 function. Now I remember you have used that matrix multiplication instead of pdist2 beforeFind Nearest Points Using Custom Distance Function. 9448. matlab Pdist2 with mahalanobis metric. Warning: Converting input data to single. Annotating Regions in the Genome (annotatePeaks. It computes the distances between rows of X. Any help. One matrix has 2 sets of coordinates. More precisely, the distance is given by. Description. . Only in mahal you are comparing each point of your sample set to the points of the reference distribution, while in pdist2 you are making pairwise comparisons based. 立即开始 30 天免费试用。. numexpr is a python package that allows for efficient and parallelized array operations on numpy arrays. 4 Descriptive measures of linear association between X and Y It follows from SST = SSR+SSE that 1= SSR SST + SSE SST where • SSR SST is the proportion of Total sum of squares that can be explained/predicted by the predictor X • SSE SST is the proportion of Total sum of squares that caused by the random effect. To do that you'd have to use the algorithm I outlined. . I'll generate some random data to serve as example, which will result in low (around chance level) accuracy. I am looking for an alternative to this in. The biggest distance using pdist2() will be from one end of the line to the opposite end of the other line. NaN NaN NaN NaN 1 2 2 NaN 3 1. It can be calculated as follows: D = A*B' + (1-A)* (1-B)'; The final distance measure can be done by testing for each pair. For example the not weighted RBF and sigmoid kernel can be computed as follows: K_rbf = exp (-gamma . computes the distance between objects in the data matrix, , using the method. Dec 24, 2014 at 12:57 @Divakar Yes, I thought about pdist2, but it wasn't allowed. [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. La función pdist2 puede usar CacheSize solo cuando el argumento Distance empiece por fast. comparison of two histograms using pdist2. Maybe the differences are due to the incorrect use of the indexes i and j. If we want to implement this in Eigen, a C++ library for doing linear algebra much in the same manner as in Matlab, we can do it in the following way,so I do that for every point, to find the distance to every other point. 23. Learn more about custom distance function, pdist, pdist2, @distfun, divergence, kl divergencescipy. Based on your location, we recommend that you select: . similarity (line 211) In spectralcluster (line 167) In spmdlang. 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. procrustes: Procrustes Analysis. I followed the documentation of MATLAB where in order to calculate Mahalanobis Distance, I have to use pdist2: "D = pdist2 (X,Y,'mahalanobis',C)" A1= [75 87 90]; A2= [99 88 100]; C = nancov. Security purpose: Face recognition is turning out to be the most common method to maintain the security of the individual/organization. between each pair of observations in the MX-by-N data matrix X and. 2277. What is the computacional complexity in asymptotic notation, O(n) , for the function "pdist2" ? 0 Comments. Learn more about matrix manipulation, distance, pdist2, matlab function, indexing, matrix, arrays MATLAB. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. 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. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. The Age values are in years,. Compute the Euclidean distance between pairs of observations, and convert the distance vector to a matrix using squareform. function D = pdist2( X, Y, metric ) DESCRIPTION . for one run, the function was called upon 27,245 times. Find the patients in the patients data set that are within a certain age and weight range of the patients in Y. I think it is not correct. D = pdist2 (X,Y,Distance) returns the distance between each pair of observations in X and Y using the metric specified by Distance. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. import numpy as np from Levenshtein import distance from scipy. 56541 0. In addition to associating peaks with nearby genes, annotatePeaks. B = [38. Application of Face Detection. This tutorial provides a quick introduction to using Spark. distfun must return an m2-by-1 vector of distances d2, whose kth element is the distance between XI. Therefore, D1(1,1), D1(1,2), and D1(1,3) are NaN values. distances (i,j) = pdist2 (blobMeasurements (i). This module contains two main interfaces which provides the following functionalities: pdist1 calculates the pairwise distances between points in one vector and returns a vector which represents the distance between the observations. Learn more about pdist2 Statistics and Machine Learning Toolbox. pdist2: Compute pairwise distance between two sets of vectors. Learn more about cosine similarity, cosine distance, jaccard similarity, jaccard distance, similarity, dissimilarity, bin counts, histogram, histcount, pdist, pdist2, distance, vectors, arrays I would like to assess the similarity between two "bin counts" (that I previously derived through the "histcounts" function), by using the "pdist2. of matlab I do not have the pdist2 function. To save memory on the device, you can separate training and prediction by using kmeans and pdist2, respectively. squareform returns a symmetric matrix where Z (i,j) corresponds to the pairwise distance between observations i and j. %. xy = rand (5, 2); distances = pdist2 (xy, xy) S = sum (distances) This code will give all sum of distances between the points, now the point having minimum distance. You can specify DistParameter only when Distance is 'seuclidean', 'minkowski', or. In any case you could use this: function MD = my_MahalanobisDistance (X, Y) [nX, mX]. m. A= [0 0, -5. D = pdist2 (X,Y,@CalcDist) function D2=CalcDist (ZI,ZJ) % calculation of distance. If observation i in X or observation j in Y contains NaN values, the function pdist2 returns NaN for the pairwise distance between i and j. Keystone paper codes. , (2, , corresponds to the distance between objects. No. 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. for low dimensional points (3 in this example) it should be more efficient to. 3 Comments. E=pdist2（X，Y-mean（X），'mahalanobis'，S）. pcshow (ptCloud. For code generation, define an. Rows of X and Y correspond to observations, That is, it works on the ROWS of the matrices. Regards, BhavyaD = pdist2 (X,Y,@CalcDist) function D2=CalcDist (ZI,ZJ) % calculation of distance. Distance 和 DistParameter 。. 5 4. MY-by-N data matrix Y. D = pdist2 (X,Y,Distance) returns the distance between each pair of observations in X and Y using the metric specified by Distance. If pdist2 is only fast because it's compiled, then your probably best served by just using it and then squaring the result, since squaring a large number of values is something Matlab does pretty efficiently anyway. Vectorizing distance to several points on Octave (Matlab) 1. In oppsite to this, sqrt(sum(t . MY-by-N data matrix Y. numpy. During a chess tournament, grand master. No checking is. Learn more about matlab, pdist2, matrixpdist2 function. pdist2 Pairwise distance between two sets of observations. 计算 X 中各对行向量的相互距离 (X是一个m-by-n的矩阵). When working with a large number of. Output argument "h" (and possibly others) not assigned a value in the execution with "getColorHist" function. In your example code you compute the distance between two points. % space. - GitHub - nolanbconaway/pairdist: A MATLAB function to compute weighted pairwise distances. [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. , is a vector of length ), (2,3),. When working with a large number of. Walter Roberson on 7 Jun 2017. The logical negation ~ gives 1 for those pairs of rows, and 0 otherwise. Very clever - I wouldn't have thought about the pdist2 function (+1). I want the haversine distance to be more specific. pdist2 Pairwise distance between two sets of observations. md","path":"README. matlab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函数。 需要注. example. 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。. We can use it as follows to perform the same computation as above: import numpy as np import numexpr as ne X_norm = np. 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.