I tried writing a cofactoring routine for n x n matrices and my code works but it shouldn't. Like, at all. But it does. Idk how and it's consistent.
Basically, my error is when assigning the sub-matrix for the cofactorization method I'm using from here :
Mathwords: Cofactor Matrix
My assignment routine should not work for the sub-matrix because of how I address the rows. under is always 0 and yet it'll assign values to the proper row. Idk how, it's magic.
Code:
#include <stdio.h>
#include <stdlib.h>
long double det(long double **x, int rank) {
/* Determinant calculator routine */
/* We initialize the resulting determinant to zero */
The function should pass the square of the first input parameter and the cube of the second input parameter back to the calling routine. I thought I could use a recursion but its not going to work.
I have faced a strange problem in File Save Routine. I have written a module to save data to binary file . I have designed a structure and put information in that and save it to file . I save multiple such records one after other. I use fwrite , fflush instructions.
The module is working fine. I have saved near about 35 such files. But in one file , the module has saved Blank Records. The file size if perfect but the file is totally blank. It has happened for only one file but need to know the reason.
In short I'm converting a floating point bilinear image resampling routine into one that only uses fixed point arithmetic. I've gotten rid of nearly all the floats now, in fact all but one and the results at the moment are in distinguishable from the floating point version. It's a maths issue really. Some pseudocode goes like this.
Code: for( int xx=0; xx<ow; xx++ ) { int_center = (ccx >> 16); int temp = xx * 2; for (j = int_center; j <= int_center + 1; j++)
[Code] ....
Where ccx is and integer error accumulator that gives me a scaled integer. Shifting down buy 16 gives me the relative pixel I need to be working on. The line just after where the inner loop begins is where I have the last remaining float. FILTER_FACTOR is essentially a percentage by which I scale the error accumulator to the correct amount.
For example.
ccx = 98303. Which is a value of 1.5 when shited down by 16 bits. Obviously I can shift it because it will round and I lose the precision. Lets say FILTER_FACTOR is 39321. Which is 60% of 1 (65535) So what I'd like to know is, is it possible to use the FILTER_FACTOR as an integer and do some fancy integer math to scale the result from (ccx - (j<<16)) by the representative amount that is FILTER_FACTOR. In this example 60%. Effectively getting 40% of (ccx - (j<<16)) At the moment FILTER_FACTOR is still a float and therefore 0.6, which of course works just fine.
I haven't found anything that small for Matrix multiplication i was just going to ask about how i would multiply to matrices together in c++ as easy as possible, so for example say a i have the following
[2 0 1 0 * [3 0 6 -1 0 2] 0 3 1 2 3 1]
How would i multiply these together. Here is the example
The program below should add two matrices using function. I have problem in the third function (the summing function). It's saying that something wrong with the array! I'm new to arrays and functions.
#include<iostream> #include<fstream> #include<conio.h> using namespace std; int matrix1 (); int matrix1 (); int add ();
I am currently trying to pass a matrix (multidimensional array) from my main into a function in a class. As usual, you have to include all array sizes, except the first. Unfortunately, the size saved under a variable. When I write it in the square brackets, it doesn't work.
Example:
//main int main () { int n = 5; random object; object.declare_variable(n); int array [3][n]; object.pass_matrix(array);
[code].....
I also tried, putting the variable 'var' in the public section above the void and declaring it as static, but still there are error messages; fewer, in my case:
...not an integer constant
So what should I do? Id like to repeat that the int n will vary, which is why I can't just directly write down the size.
Two different matrices will be read from text files (input1.txt, input2.txt) and they will be stored in two dimensional arrays (matrix1, matrix2) and one dimensional arrays (array1, array2). Our aim is to obtain the matrix multiplication using two dimensional and one dimensional arrays.
You are asked to write the main and the following functions. The definitions of the functions are given in the skeleton code.
int read_file(ifstream& in_file, int &row, int &col, double *array, double **matrix) int write_file(ofstream& out_file, int row, int col, double **matrix) void print_matrix(double **matrix, int row, int col) void print_array(double *array, int row, int col) void multip(double **matrix1, double **matrix2, double **result, int k, int m, int n) void multip_array(double *array1, double *array2, double *array_result, int k, int m, int n)
You are going to obtain the input and output files as command line arguments
input1.txt : 3 4 2 3 4 5 1 3 5 4 0 4 4 7
The first element in the first line represents the number of rows (3) and the second element represents the number of columns (4) of the matrix (the result file will have the same format).
thats my homework and here is the code i wrote from the sceleton code they gave me :
#include <iostream> #include <fstream> #include <string> using namespace std; int read_file(ifstream& in_file, int &row, int &col,/* double *array,*/ double **matrix)
[Code] ....
I didn't understand the array part but even when i exclude the array part i get the program has stopped working message. My os is windows7 ultimate with mingw installed and i compile the program using g++ command in cmd with the arguments input.txt input2.txt resultt.txt
I'm taking a programming class and currently we're doing data structures. Today, we discussed how to save square matrices column-wise with data structures. The teacher said that after the first few steps where you declare the structure, allocate the matrix, free it and get the dimension (which mostly make sense to me I think), you have to "get" and "set" the matrix by putting in something like
Code: void setMatrixEntry(Matrix* A, int i, int j, double Aij) { A->entries[i+j*A->m] = Aij; }
I would like to program a simple finite element solver in c++ (I'm a relatively new programmer by the way). This is the issue, I have a text file with all the information of the model arranged in matrices; an input file would look something like this:
I would like to create N matrices of dimension (n,k) simultaneously. Lets say for example that N=3. I read the command a[n][k][N] but I don't understand how to use it.
I know that for some of you this question is silly but I' m new to this language and I have noone else to ask.
The program adds 2 matrices that are 3x3 using arrays and then stores them into another matrix (array) and then it's edited to show a diagonal line of "0" through it, btw I'm pretty new to programming....
insert Code: #include <iostream> using namespace std; int main() { int x[3][3],y[3][3],c[3][3],i,j; cout<<"Enter your numbers"<<endl;
[Code] .....
It works almost just fine lol, Except that the first portion of the diagonal line does not become zero and instead displays the normal addition result.....
I've been assigned to build a program which completes mathematical operations using matrices. I have to use dynamically allocated 2d arrays, and can only use * to dereference and not []. I have this code so far, but the multiply_matrix function does not work with most values. I've looked at other similar posts, which have a similar algorithm to mine, but mine does not work for some reason.
/* *(*matrix(matrix+i)+j) */
#include <iostream> //for sleep() which allows user to see messages before screen is cleared #include <unistd.h> using namespace std;
I am unable to input the correct form for matrices multiplication. I have an exam tomorrow in which I need to use this.
Code:
#include <stdio.h> #include <conio.h> int main() { float a[10][10], b[10][10], c[10][10]; int i, j, k, l, n=0, m=0, x=0, y=0, sum=0; printf("Enter the number of rows and collumns of the first matrix"); scanf("%d %d", &n, &m);
I am trying to perform columnSum and rowSum, as well as twoDadd and twoDSubtract using the arrays defined in my driver. How would I do that using A and B in my driver?
I am working on a number of utility functions for two dimensional arrays of integers, or matrices. However I am having a problem with segmentation faults, most likely due to errors in using malloc in functions like copyMatrix.
Code: matrix_utils.h~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ //This function checks if two matrices are equal int isEqual(int **A, int **B, int n);
//This function returns one row of a matrix int * getRow(int **A, int i, int n);
//This function returns one column of a matrix int * getCol(int **A, int j, int n);
I am using the gnu glpk library to calculate a linear program for my matrices. Why I get the error message exit code 3 which apparently means "The system cannot find the path specified"?
