Questions tagged [matrices]
The matrices tag has no summary.
20 questions
0
votes
0
answers
81
views
Organizing Complicated Matrix Traversal?
The following are some examples that you may see in an intro to programming course:
Print the elements of an nxn array...
Spiraling in from the outside
Spiraling out from the center
Zig zagging from ...
- 37
3
votes
0
answers
111
views
What's the most practically efficient way to store differences in adjacent matrix values?
I am implementing a certain algorithm that works like this:
Create a closed contour (list) of elements in a matrix, where closed means that the last element is adjacent (by row, column) to the first.
...
- 129
3
votes
3
answers
139
views
Say we have a group of N person, and each person might want to sell or buy one of the M items, how to find a closed path among them for an exchange?
Say we have N persons and M items (when a person has a certain item, she usually only has one piece). For example,
person 1 has item A, C, D, and wants item F
person 2 has item B, C, and wants E
...
- 141
2
votes
2
answers
997
views
Formats for Storing Sparse Matrices
For storing sparse matrices I know there are multiple formats that are common, like COO, CSR, DIA, ELL, HYB, etc. (Link to some storage formats), but I haven't found that any of these stores the ...
- 123
4
votes
3
answers
1k
views
How to represent a three-dimensional (or more) data structure in a terminal?
I am working on a library that allows the creation and manipulation of Vectors (lists with a known length), Matrices (lists of lists with known dimensions), and three-, four- etc. order Tensors (lists ...
- 4,947
1
vote
1
answer
465
views
Question about the uses of matrices in games and 3D graphics [closed]
So I know that matrices are used extensively in the field of games and 3D graphics, for example, you need to know how to do matrix multiplication if you want to understand how scaling an object works, ...
- 119
25
votes
2
answers
11k
views
Why does expressing calculations as matrix multiplications make them faster?
In Google's MNist tutorial using TensorFlow, a calculation is exhibited in which one step is equivalent to multiplying a matrix by a vector. Google first shows a picture in which each numeric ...
- 1,273
3
votes
1
answer
195
views
How can you write an activation function in a neural network to handle a layer architecture of arbitrary dimensions?
I am making a neural network in Clojure that can take an array of integers,and return a data structure representing the layers of a neural network: so (make-layers [1 4 5]) would evaluate to:
[[0] ...
- 290
2
votes
4
answers
114
views
Similar multidimensional array detection
I'm looking for some sort of algorithm so I can quickly identify similar matrices, the matrices are not stored permanently so I'd need a way of mapping each matrix to an easily stored values, after ...
- 21
-1
votes
3
answers
137
views
number of square matrices in a non-square matrix [closed]
i was wondering if there is any formula to calculate the number of square matrices present in a square matrix.
e.g
a 3x2 matrix has 3 square matrices that are (2x2, 1x1, 1x1)
a 6x3 matrix has 2 ...
- 11
1
vote
0
answers
2k
views
How to loop through array bidimensional in diagonal according to a position in degrees
The title could be no self-explanatory enough but I need some conceptual help in order to implement a solution to go through an array:
I'm developing a program to calculate the "most shadepath" route ...
- 113
3
votes
1
answer
258
views
Why use atomic vectors or matrices in R at all?
In reading Hadley Wickham's Advanced R I learned about the difference between atomic vectors and lists; and matrices/arrays and dataframes. This is something I hadn't really appreciated before, and ...
- 161
0
votes
1
answer
784
views
How to display an inward spiral matrix
Suppose I have the following matrix with values 1-25 as input to my program.
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
The inward spiral should give me the output 13 ...
- 135
0
votes
1
answer
847
views
Two dimensional matrix-like data type using lists and/or mutable lists
I am trying to think of an implementation of a two dimensional matrix-like data type.
Normally I would take an array of arrays but I'm bound to a relatively low language level which only provides ...
- 162
1
vote
1
answer
234
views
Matrix distribution to process grid
I need to write a program, which will perform LU-decomposition, etc. The problem is that I don't know about the preferred way to distribute the loaded matrix from the root process to other processes. ...
- 327