I need to calculate a rotation vector out of the data i get from Sensor.TYPE_ORIENTATION. The sensor data is defined like this: the values have to be recalculated to become a correct 3d position: values[0]: Azimuth, angle between the magnetic north direction and the Y axis, around the Z axis (0 to 359). 0=North, 90=East, 180=South, 27...
So I found this thread that was extremely helpful in traversing an array diagonally. I'm stuck though on mirroring it. For example: var m = 3; var n = 4; var a = new Array(); var b = 0; for(var i = 0; i < m; i++) { a[i] = new Array(n); for(var j = 0; j < n; j++) { a[i][j] = b; b++; } } for (var i = 0; i < m + n - 1; i+...
I want to vectorize the following MATLAB code. I think it must be simple but I'm finding it confusing nevertheless. r = some constant less than m or n [m,n] = size(C); S = zeros(m-r,n-r); for i=1:m-r+1 for j=1:n-r+1 S(i,j) = sum(diag(C(i:i+r-1,j:j+r-1))); end end The code calculates a table of scores, S, for a dynamic...
Hello, I am trying to understand what is a chain matrix multiplication and how it is different from a regular multiplication. I have checked several sourcers yet all seem to be very academically explained for me to understand. I guess it is a form of dynamic programming algorithm to achieve the operation in an optimised way but I didn'...
I thought I understood perfectly how the vertices go through the 3d pipeline but in this article http://msdn.microsoft.com/en-us/library/ee418867%28VS.85%29.aspx a new matrix multiplication appears appears that makes the transition from projection space to clip space. I thought that projection space = clip space ( as in the case of Open...
Question is simple for an expert Integer[][] res= new Integer[][] {.....hard code some values here on 2 dim...} How to return here 2 rows and 3 cols like this 1 2 3 4 5 6 ...
I am searching a 2D matrix (or bitmap) class which is flexible but also fast element access. The contents A flexible class should allow you to choose dimensions during runtime, and would look something like this (simplified): class Matrix { public: Matrix(int w, int h) : data(new int[x*y]), width(w) {} void SetElement(int...
I have two vectors describing rotations; a start rotation A and a target rotation B. How would I best go about interpolating A by a factor F to approach B? Using a simple lerp on the vectors fails to work when more than one dimension needs to be interpolated (i.e. produces undesirable rotations). Maybe building quaternions from the rota...
Does anyone know how to count the number of times a value appears in a matrix? For example, if I have a 1500 x 1 matrix M (vector) which stores the values of weekdays (1 - 7), how could I count how many Sundays (1), Mondays(2), ... , Saturdays(7) are stored in M? ...
Hello, I can easily draw the projection of a 3D set of points onto the plane with normal vector (1,1,1), by using the matrix (-sqrt(3)/2 sqrt(3)/2 0) (-1/2 -1/2 1). I want to do the same thing, but for a projection onto an arbitrary plane with normal vector (a,b,c) instead of (1,1,1). How to find the matrix...
Unions aren't something I've used that often and after looking at a few other questions on them here it seems like there is almost always some kind of caveat where they might not work. Eg. structs possibly having unexpected padding or endian differences. Came across this in a math library I'm using though and I wondered if it is a total...
I have written a TestSuite to find out how to calculate the rotation angles from the data you get in SensorEventListener.onSensorChanged(). I really hope you can complete my solution to help people who will have the same problems like me. Here is the code, i think you will understand it after reading it. Feel free to change it, the main...
I have a dense matrix where the indices correspond to genes. While gene identifiers are often integers, they are not contiguous integers. They could be strings instead, too. I suppose I could use a boost sparse matrix of some sort with integer keys, and it wouldn't matter if they're contiguous. Or would this still occupy a great deal of...
As an example, here is a way to get a matrix of all possible outcomes of rolling 4 (fair) dice. z <- as.matrix(expand.grid(c(1:6),c(1:6),c(1:6),c(1:6))) As you may already have understood, I'm trying to work out a question that was closed, though, in my opinion, it's a challenging one. I used counting techniques to solve it (I mean by...
Hi, I am trying to find the easiest way to add, subtract a scalar value with a opencv 2.0 cv::Mat class. Most of the existing function allows only matrix-matrix and matrix-scalar operations. I am looking for a scalar-matrix operations. I am doing it currently by creating a temporary matrix with the same scalar value and doing require...
I have an OpenCV matrix of double (CV_32F) values. I'd like to save it to the disk. I know, I could convert it to an 1-Channel 8-bit IplImage and save it. But that way, I loose precision. Is there a way to save it directly in the 32-bit format, without having to convert it first? It also would be nice, if the resulting file would have an...
I want to display data in a reporting services matrix. It is an access peak matrix, in a way that days are rows, and hours are columns. My procedure returns data like this: Day / Hour / Peak 2010-05-01 00:00:00.000 2010-05-01 00:00:00 0 2010-05-01 00:00:00.000 2010-05-01 01:00:00 0 2010-05-01 00:00:00.000 2010-05-01 02:00:00 0 2010-05-0...
Hi all, So I have a 3D image that's getting transformed into a space via an affine transform. That transform is composed of the traditional 4x4 matrix plus a center coordinate about which the transform is performed. How can I invert that center point in order to go back into the original space? I have the coordinate, but its a 1x3 ve...
Hi! I have 15 input fields, each one is in its own table cell. They are in the table because I need them to look like a matrix. The question is now - when an user enters data in those input fields and hits submit, how do I transfer that data into a matrix? The real problem is that from that input data I need to find min values in each...
What is the matrix of sobel operator of size 3x3 if the operator is said to be diagonal (Left or right diagonal)? EDIT: or may be with more bigger size ...