You have the # lines as a separation between your matrix. So if you loop line by line on your file, you can separate the matrix with this # lines, and built them : file = open(“file.txt”, “r”) lines = file.readlines() At this point, lines is a list. lines[i] is the line n° i+1 as … Read more
I wanted to use my own implementation of the Strassen optimization for matrix multiplication. It is highly optimized and hence has almost no pedagogical use but then I remembered that Wikipedia has actual C code in the Strassen-matrix-multiplication entry. The implementation there is not the best: it has no fallback to the naive algorithm if … Read more
This is an algorithm which uses Lapace expansions, which recursively computes the determinant of an n x n matrix by computing n determinants of (n-1) x (n-1) subminors. The determinant of the 2 x 2 matrix should be obvious. There are better ways to do that, like LU decomposition. 1 solved Understanding of a specific … Read more
If you don’t know the external indice, you’d have to loop through every element in the array and compare the values of their x/y coordinates to your given coordinates, then return the ID when you find a match, or some sentinel value if you reach the end without finding a match. 0 solved Accesing 2d … Read more
If I understand correctly, you can generate all permutations of column indices with perms, and use the result to index into the matrix: M = magic(3); % // example matrix pp = perms(1:size(M,2)); % // each row is a permutation for p = pp.’ %’// “for” loops over columns, so transpose pp permuted_M = M(:,p); … Read more
If you could please point me towards some reading material that can teach me how to add, remove, get and iterate over the elements of the method suggested by you. Arrays don’t support those operations. To add and remove elements you really need to use a List such as ArrayList. List<List<Integer>> list2d = new ArrayList<>(); … Read more
First of all, in general, var <- expr evaluates the R expression expr and assigns the result to the variable var. If the statement occurs inside a function, then var becomes a function-local variable, otherwise, it becomes a global variable. c(0,0,0,1,0,1,0,1,1,1,1,0) Combines 12 double literals into a double vector in the order given. matrix(c(0,0,0,1,0,1,0,1,1,1,1,0),4,3, byrow=T … Read more
I found the answer i was looking for from below link. [http://hawkee.com/snippet/10086/] for anyone who is interested in this finding out i will post it here. There is second solution for this also using array within array. Which i will post below this, <?php class Matrix { public $arr, $rows, $cols; function Matrix($row, $col) { … Read more
Ok, as now we have seen your attempt, I would suggest you to grasp some concepts of Python and get an understanding of Python’s libraries and builtins, esp, in this case, you need to understand zip and all. You also need to understand about iterable and List Comprehension. Zip is a wonderful function, and comes … Read more
You have put the k=k+1 at a wrong place. It is the correct code: stab1=zeros(1,4991); k=0; for ii=-0.6:0.01:-.3 m=0; for jj=0:0.01:1.6 m=m+1; if …. (some condition) stab1(k*161+m)=1; end end k=k+1; end Now it has 4991 elements. solved How many elements the output matrix should have in this code? [closed]
There are several errors. For example you use variable n before its initialization matrix=(int**)malloc(n*sizeof(int*)); scanf(“%d”,&n); There must be scanf(“%d”,&n); matrix=(int**)malloc(n*sizeof(int*)); You never set variable flag to 1. So it always has value equal to 0 independing of the matrix values. The break statement in this loop for(j=0;j<n;j++) { if(matrix[i][j]!=1 && matrix[j][i]!=0) flag=0; break; } have … Read more
Many options here. Unfortunately you don’t show any effort to resolve the problem or even to make it clear and reproducible. For example, using ifelse : dat <- read.table(text=””aaa” 28 “aac” 8 “aag” 20″) dat$V1 <- with(dat,ifelse(V1 %in% c(‘aaa’,’aag’),’K’,’N’)) dat V1 V2 1 K 28 2 N 8 3 K 20 EDIT If I want … Read more
Start from this simple skeleton: class Matrix: def __init__(self, matrix): self.matrix = matrix def double_diagnonal_entries(self): # do calcs return self.matrix Note, that if you need to implement some basic matrix ops like addition you might consider operator overloading such as: def __add__(self, another_matrix): # do the math return sum_matrix solved Create a class that takes … Read more
OK, so assuming you want to store the results in c, with dims 256, 50, do something like: for(int i = 0; i < 256; ++i) for(int j = 0; j < 55; ++j) { c[i][j] = compute_correlation(matrixA, i, matrixB, j); } with compute_correlation a simple for loop that will compute the value according to … Read more
set.seed(1) options(digits=4) mA <- matrix(runif(16), 4, 4); mA [,1] [,2] [,3] [,4] [1,] 0.266 0.202 0.6291 0.687 [2,] 0.372 0.898 0.0618 0.384 [3,] 0.573 0.945 0.2060 0.770 [4,] 0.908 0.661 0.1766 0.498 mB <- matrix(runif(16), 4, 4); mB [,1] [,2] [,3] [,4] [1,] 0.718 0.935 0.2672 0.870 [2,] 0.992 0.212 0.3861 0.340 [3,] 0.380 0.652 … Read more