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
Using the old fashioned (unsigned) multiplication instruction in x64 assembly multiplies RAX (64 bit register) by a 64 bit register. The answer is stored in RDX:RAX (i.e. the answer is 128 bits). Is there any way, using native c++ to get the value in RDX (higher 64 bits)? One I can think of is: right/(limit/left) e.g. if we are limited to a byte then 97*123 would overflow:
97/(255/123) = 46 times, which is RDX's (if it was one byte) value. But this is too inefficient. Is there a fast way?
I am new to C programming and I am just wondering how to multiply / divide two different variables which the user type in as the promt is asking like this:
Code: void inmatning3 (double *a, double *b) { printf("Mata in tv217 stycken flyttal: "); /* asks you to type in 2 numbers */ scanf("%lf %lf", a, b); }
When you've enterd the two numbers I need to eather multiply or divide the two variables "a" & "b" .....
I've been working on this program to create a simple desk calculator for a school assignment, and I managed to finish. All we had to do was add, subtract, multiply, and divide positive integers - and I was able to do that just fine. This program got me thinking though, because I do not know how to write commands to multiply/divide negative numbers.
In fact, when I divide a number like 21 by 4, it comes out to 5 because I don't know how to allow it to compute remainders (which wasn't a requirement for my program). This intrigued me so I've been trying to figure it out for the last few days but to no avail. Here's my code:
Code: void flush_buffer(){ int ch; while ((ch = getchar()) != ' ' && ch != EOF);
[Code]....
And just know that my code works perfectly fine, I'm not here for troubleshooting it. I just want to know what I can change to allow negative values to be correctly computed.
#include <iostream> using namespace std; int main(){ int polje[8][8];{ for(int i=0;i<8;i++) for(int j=0;j<8;j++) {
[Code] .....
I don't get any errors,the program works. The problem is that it doesnt work how it should. This is a simple program that multiplies 2 variables(i and j)that go from 0 to 7. The problem I have is with the logical operators,i want the program to skip multiplication with 0 and when the 2 variables are the same value. When i try using only 1 logical operator it work.
I'm building two DLLs - let's call them DLL_A and DLL_B. DLL_A builds as a standalone entity but DLL_B needs to link to the lib file for DLL_A (i.e. it imports some functionality from DLL_A). While linking DLL_B I see lots of errors taking the following form (bear in mind that port.cpp and port.h are source files in DLL_B:-
I'm not sure if I'm reading that correctly but to me, it seems to be saying that some STL components are somehow getting exported from DLL_A (std::vector maybe?? Or std::string??) and that they conflict with similar objects already in port.obj. Sure enough, when I used dumpbin /EXPORTS on DLL_A there did seem to be some evidence that that was true. So my next step was to examine the source code for port.obj. Of course, strictly speaking I should be examining some code from DLL_A but it has hundreds of source modules so I figured that I should start by identifying whatever it is in DLL_B that's throwing up the conflict (since I at least know which module the conflict is in!).
When I examined the source files for port.obj, std::string seems to get used quite often - but fortunately I could only find one occurrence of std::vector.
In port.h it occurs here:-
Code: class DLL_B_API Port : public boost::noncopyable { public: // c'tors + d'tors int get_connections (std::vector<std::string> &) const; // rest of class
In port.cpp it occurs here:-
Code: int Port::get_connections (std::vector<std::string> & c) const { if (!port_engine.available()) { c.insert (c.end(), _connections.begin(), _connections.end()); return c.size(); } return port_engine.get_connections (_port_handle, c); }
Is there anything in there that would be causing the above linker error? It's entirely possible that I'm looking in the wrong place but I suppose I've got to start somewhere....
I just found a possible clue in one of the header files for DLL_A, where I found this class declaration:-
Code: namespace PBD { class DLL_A_API Searchpath : public std::vector<std::string> { // Whatever... }; }
Might that be causing std::vector<std::string> to get exported?
I'm trying to get my C program to compile but it's not working at all. I've programmed a little in C++ before but I'm not used to C. Here's my program so far:
Code: int main(void){ // Establishes variables int num1, num2, product; float quotient;
[Code] .....
It keeps giving me an error message as follows:
"/usr/bin/ldrelabwk2: file format not recognized; treating as linker script /usr/bin/ldrelabwk2:1: syntax error collect2: ld returned 1 exit status"
I have to write a program, that multplicates very large numbers (out of range of long int). It's said that i need to use arrays and read the numbers as strings. My problem is to end function called "mnoz:, because i don't know how to sum the multiplicated values of arrays a and b.
"fatal error LNK1169: one or more multiply defined symbols found"
Here's my code:
#include "stdafx.h" #include <iostream> using namespace std; int main () { cout << "Avoiding Technology" << endl; bool status = true; int location; int a,b;
I have a code in here that u will multiply the number of seat and the number of ticket. I think I got the correct return value but it's still not working when i times it it always = 0 ...
#include<iostream> #include<iomanip> #include<string> #include<stdio.h> #include<fstream> int getBill(int seat); int getPos(char seat);
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 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
Create a program that adds, subtracts, multiplies, or divides two integers. The program will need to get a letter (A for addition, S for subtractions, M for multiplication, or D for division) and two integers from the user. If the user enters an invalid letter, the program should display an appropriate error message before the program ends. If the letter is A (or a), the program should calculate and display the sum of both integers. If the letter is S (or s), the program should display the difference between both integers. When calculating the difference, always subtract the smaller number from the larger one. If the letter is M (or m), the program should display the product of both integers. If the letter is D (or d), the program should divide both integers, always dividing the larger number by the smaller one."
And here is the test data. I am posting the results from my desk-check table.
operation first integer second integer answer A 10 20 30 a 45 15 60 S 65 50 15 s 7 13 6 G -1 M 10 20 200 d 45 15 3 d 50 100 2
Then, I transferred my program into a source file. Here it is:
//Exercise16.cpp - display answer of two integers
#include <iostream> using namespace std; int main() { //declare variables int firstInteger = 0;
[Code] ....
After putting in the data, everything worked fine, except the last two operations, which are M (multiplication) and D (division). All the answers for the last two operations essentially give me a 0.
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; }
