matrix

问题 I have a 2D array of zeros with some positive integers at (1,6) and (2,7): [[0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] [0. 0. 0. 0. 0. 0. 2. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.] [0. 0. 0. 0. 0. 0. 0. 2. 0. 0. 0. 0. 0. 0. 0. 0. 0.] [0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.]] And I want to filter the array by a custom kernel: [[1 0 1] [0 1 0] [0 1 0]] I want to filter the array with this kernel and when 2 or 3 of the ones in this kernel are multiplied by a positive integer, I want

问题 all, I have a correlation matrix of 21 industry sectors. Now I want to split these 21 sectors into 4 or 5 groups, with sectors of similar behaviors grouped together. Can experts shed me some lights on how to do this in Python please? Thanks much in advance! 回答1: You might explore the use of Pandas DataFrame.corr and the scipy.cluster Hierarchical Clustering package import pandas as pd import scipy.cluster.hierarchy as spc df = pd.DataFrame(my_data) corr = df.corr().values pdist = spc.distance

问题 all, I have a correlation matrix of 21 industry sectors. Now I want to split these 21 sectors into 4 or 5 groups, with sectors of similar behaviors grouped together. Can experts shed me some lights on how to do this in Python please? Thanks much in advance! 回答1: You might explore the use of Pandas DataFrame.corr and the scipy.cluster Hierarchical Clustering package import pandas as pd import scipy.cluster.hierarchy as spc df = pd.DataFrame(my_data) corr = df.corr().values pdist = spc.distance

问题 I have a question regarding the use of BLAS parallelized matrix product in R (being the default matrix product at least since R-3.4, maybe earlier). The default behavior (at least on my machine) is now for the matrix product (c.f. example below) to use all the cores available on the machine, which can be a problem. Do you know how to control the number of cores used for standard matrix product in R? Thanks in advance Example: n=10000 p=1000 q=5000 A = matrix(runif(n*p),nrow=n, ncol=p) B =

问题 I am creating a simple Matrix class. I am trying to add an unnamed template parameter to make sure it is used with integral types #include <string> #include <vector> #include <boost/utility/enable_if.hpp> #include <boost/type_traits/is_scalar.hpp> template <typename T, typename = typename boost::enable_if<boost::is_scalar<T> >::type> class Matrix { public: Matrix(const size_t nrow, const size_t ncol); private: const size_t nrow_; const size_t ncol_; std::vector<std::string> rownames_; std:

问题 I am creating a simple Matrix class. I am trying to add an unnamed template parameter to make sure it is used with integral types #include <string> #include <vector> #include <boost/utility/enable_if.hpp> #include <boost/type_traits/is_scalar.hpp> template <typename T, typename = typename boost::enable_if<boost::is_scalar<T> >::type> class Matrix { public: Matrix(const size_t nrow, const size_t ncol); private: const size_t nrow_; const size_t ncol_; std::vector<std::string> rownames_; std:

问题 Is it possible to resize by pulling the matrix on the 4 side of the view? I can resize from a single point to a ratio like this. The example above works as follows: protected boolean onTouchDown(@NonNull MotionEvent event) { oldDistance = (float) Math.sqrt((midPoint.x-event.getX()) * (midPoint.x-event.getX()) + (midPoint.y-event.getY()) * (midPoint.y-event.getY())); ... } float newDistance = (float) Math.sqrt((midPoint.x-event.getX()) * (midPoint.x-event.getX()) + (midPoint.y-event.getY()) *

问题 Assume the matrices to be of the form, The required output on stdout using C language should be My code: #include<stdio.h> int main(void) { int size, i=0, j=0; printf("Enter the size of the array:"); scanf("%d",&size); int A[size][size], B[size][size], C[size][size]; //Entering the values in A[][] printf("enter the elements of Array A:\n"); for(int i=0; i<size; i++) for(int j=0; j<size; j++) scanf("%d",&A[i][j]); //Entering the values in B[][] printf("enter the elements of Array B:\n"); for

问题 I have some data in a somewhat inconvenient format. It is saved as a matrix, with all column vectors being characters. datamatrix <- structure(c("1", "2", "3", "4", "0.9301", "0.93", "0.9286", "0.9209", "0.9", "0.8064", "0.7947", "0.7607", "0.8042", "0.7847", "0.7832", "0.7578", "0.7487", "0.7105", "0.6566", "0.5951", "0.6951", "0.677", "0.6588", "0.5922", "0.6889", "0.6471", "0.6524", "0.5932"), .Dim = c(4L, 7L)) My aim is to convert this matrix to a dataframe and the column vectors to the

问题 I have some data in a somewhat inconvenient format. It is saved as a matrix, with all column vectors being characters. datamatrix <- structure(c("1", "2", "3", "4", "0.9301", "0.93", "0.9286", "0.9209", "0.9", "0.8064", "0.7947", "0.7607", "0.8042", "0.7847", "0.7832", "0.7578", "0.7487", "0.7105", "0.6566", "0.5951", "0.6951", "0.677", "0.6588", "0.5922", "0.6889", "0.6471", "0.6524", "0.5932"), .Dim = c(4L, 7L)) My aim is to convert this matrix to a dataframe and the column vectors to the