I try to write code for one problem which is worked with the matrix.I have written in specific size 5 by 5 and I know the general formula for these matrix based on dimension,I want to write a general form that take the matrix size and then create my favor matrix.However,when I write like below the following error is appeared
int m;
cin>>m;
int A[m][m];
Error: m must be constant
I would like to initialize a N-dimensional matrix by specifying the dimension N.
To be clearer :
if N=2 I use to do that :
std::vector<std::vector<double>> myMatrix;
if N=3 :
std::vector<std::vector<std::vector<double>>> myMatrix;
and so on...
What I would like is to give N as an argument of a function which construct a N-dimensional empty matrix. Is that possible ?
I am really desperate on trying to make my code work. The code is to find the eigen values of any given matrix of dimension NxN. The input can be the diagonal of any NxN matrix alongwith its subdiagonal. The code works fine for N~350 or so but when i go beyond that these errors appear.
First-chance exception at 0x00425ea4 in divide.exe: 0xC0000005: Access violation writing location 0x01141000.
Unhandled exception at 0x00425ea4 in divide.exe: 0xC0000005: Access violation writing location 0x01141000.
But as i have never declared any variable statically and when i dynamically allocating memory with variables it should work like it does for smaller N values.
So I'm making setTimeout and setInterval functions.
I have this remember function (that is part of Timing class) which takes a function pointer and a void pointer, which are remembered in that object.
Another (timing) function of that object is called in every loop of the program and when specific time passes that function calls the remembered function whit the remembered void pointer as argument.
The problem is that the functions that need to be called require unknown multiple parameters, so what I need to do is make a new class that will store the needed arguments. I make the function that needs to be called and that storage object and pass pointers to them to my remember function, when the remembered function is called it stores the data from storage object in new variables and dose it's thing.
I have an image of size 640x480 pixels. It's possible to obtain the dimension in mm of one pixel from that image given only that size?I do not have the size of the image in mm,however.
View 5 Replies View Relatedi want to know how i can solve this question? do i need to create a class or write the program codes.
View 12 Replies View RelatedI am trying to create a rectangle with 3*5 dimension which would look like:
#####
#####
#####
I wanted to use for, and do while loop for that programming. I couldn't been able to create my desired dimension of 3*5.
//complier directives
#include<iostream>
#include<cstdlib>
using namespace std;
//main body
int main () {
//local identifiers
//complier directives
[Code] .....
I just want to know the code of the program: Write code to accept matrix as aurgument and display its multiplication matrix which return its multiplication matrix.
View 1 Replies View RelatedI am trying to figure out the syntax to dynamically allocate a single dimension of a triple dimensional array. Basically i have a 2D array of structs. but each struct is an array (basically rows of the information). The rows of this structure need to be allocated dynamically, but the height and width of the overarching structure are static.
Basically: Struct * ts_FieldInfo[100][100] = new Struct[Class.returndataitems()];
Want to initialize a local one dimensional array. How can I do the same without a loop?
Found from some links that
int iArrayValue[25]={0};
will initialize all the elements to ZERO. Is it?
If yes then can we write below code to initialize the elements to a non-ZERO value?
int iArrayValue[25]={4};
Do we have some other way to initialize an array to a non-ZERO value? Memset can initialize the element to ZERO.
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.
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 want to assign a matrix to submatrix of a bigger matrix.
ublas::matrix<int> A(8,5);
ublas::matrix<int> B(2,5);
for(size_t i=0;i<A.size1();++i)
for(size_t j=0;j<A.size2();++j)
A(i,j)=i*A.size2()+j+1;
for(size_t i=0;i<B.size1();++i)
for(size_t j=0;j<B.size2();++j)
B(i,j)=i*B.size2()+j+5;
ublas::matrix_range<ublas::matrix<int> > a(A,ublas::range(0,2),ublas::range(0,5));
a=B;
and it works.
but if the matrix is compressed_matrix type, there's something with it. the error log as below:
Check failed in file boost_1_48_0/boost/numeric/ublas/detail/matrix_assign.hpp at line 1078:
detail::expression_type_check (m, cm)
terminate called after throwing an instance of 'boost::numeric::ublas::external_logic'
what(): external logic
Aborted
I'm not sure this is a bug or not.
I would like to print a multiplication table, with the dimension n given as input. I attached how the table looks like for n=7.
How do you output the character "-" in that sequence? The first and last numbers have 13 "-" characters before and after them, but the numbers in between have 8 "-" characters.
I am trying to read in data from a text file and store it inside a 3D array. The text file looks like this:
bar bell orange
bell bell 7
lemon cherry cherry
I can read in the data fine, but how to store it inside the array. My array looks like : [ Char slotMachine[10][3][8]; ] T
he dimensions are Row, Column, and symbol. There are 10 rows and 3 columns inside the file. The third dimension is supposed to hold the symbols as a C-style string.
This is what I have been trying:
char symbol[8];
int rowIndex = 0, colIndex = 0;
While(fin.good()){
fin >> symbol;
slotMachine[rowIndex][colIndex][] = symbol;
rowIndex++;
colIndex++;
}
I know that i'm not storing the symbol right. How to correctly store it inside the third dimension.
I have a set of n- dimension point store in `vector< vector<double> >`
ex A[0][1].............[N], and A[0][0] = X, A[0][1] = Y, A[0][2] = Z
and I want to sort the vector of all of the dimension
ex sort X, Y, Z ,.........N in ascending order
ex A[0] = (1,5,3), A[1] = (3,2,1) A[2] = (2,8,4) after sorting
index: 0 1 2
A[0] = (1,5,3), A[1] = (2,8,4) A[2] = (3,2,1)
original index : 0 2 1
I find that `sort(vector.begin(), vector.end())` can sort it but how can I record the original index with a additional vector?
Is there a algorithm or C++ feature can solve it?
I have tried to solve it with a class wrapper it but I don't know how to write the compare function.
class point{
public:
point(int totalLength = 0, int elementLength = 0);
vector<vector<double> > pointSet;//store the n-D points
vector<double> pointIndex;//store the index
};
point::point(int totalLength, int elementLength){
pointSet.resize(totalLength,vector<double>(elementLength, 0));
pointIndex.resize(elementLength);
}
I want to save the char[8][8] // fixed size 2 dimension array
to a vector
such as
vector<?????> temp;
is there anyway to approach this?
I am writing a class which loads a bitmap image into a one dimension char* array.
This class has methods to allow for resampling and cropping the image before saving the bitmap image. It works perfectly for all images in which the width is divisible by 4. However when the width is not divisible by 4 the resulting bitmap is all mixed up.
I have spent much of the day googling this problem but to no avail. I know it is a problem with making sure the scanlines are DWORD aligned, and I believe I have done that correctly. I suspect that the problem is that I need to take the padding into account during the crop for loops but am lost to how to do this.
BTW: Coding on Linux using GCC
The following code is a cut down version from my bitmap class. I have removed methods which are not needed to make reading a little easier.
#include "BMP.h"
// FIXME (nikki#1#): Portrait bug on images of specific sizes
// TODO (nikki#1#): Memory leak checks
// THIS METHOD WRITES A BITMAP FILE FROM THE CHAR ARRAY .
bool BMP::saveBMP(string fileName, string *err) {
FILE *filePtr;
[Code]...
I have to prepare a project. But I don t know how can I do this. Program will find a matrix P for a square matrix A such that P^-1 A P ....
View 15 Replies View RelatedI need to create a main function with a one dimension dynamic array with float data type. The total number of array elements must be controlled by a user input from the keyboard. Test data is three different lengths 3,6,9 of the array. The lengths have to be set up at run time from users input. I understand how to create dynamic array but not where the user inputs the length of the array. How would I implement this?
View 6 Replies View RelatedI have the following code
#include <stdio.h>
#include <stdlib.h>
#include <postgresql/libpq-fe.h>
[Code].....
i dont usually write console programs, and i cant seem to find out how one parses an unknown number of arguments with cin.
the program receives an unknown amount of integers in stdin, and i need to parse them withouth hanging.
Unfortunately, stdin is a async. stream and blocks, if it doesnt find any integers left.
I cant use peek() or seek() either, as both are async, too, (which makes me wonder what their exact use is?).
I'm doing some file input/output work here in C and received this warning during compilation (GCC). My research indicates that this error is in response to white space or a character cancellation function or something like that. I'm not 100% sure exactly what it means. My code works fine, but the following warning does appear.
Code:
warning: unknown escape sequence: '40'
Here's my code (excluding a bunch of comments at the bottom of the file).
Code:
#include <stdio.h>
int main(void){
FILE *file;
file = fopen("Running Practice.c", "a");
fprintf(file, "Testing...
");
fclose(file);
}
I believe the error I received has to do with either the ' ' I used when appending text to my file, or something to do with there being a space in the file name itself.
I want my program to be able to read text files in the format:
number number
number number
number number...
and so on, so there are two columns of values. The problem I'm having is, there are a lot of numbers in the file, and it can vary. The program needs to read the numbers, put one column into one array, and the other in another, perform some operations on it all, and eventually pop out two different arrays. In other words, after I've got these arrays, I don't need them for much longer. I was hoping I could dynamically allocated some arrays to store the numbers and just free them as soon as I'm done with them.
If the file wasn't of such variable size or if it was guaranteed to be under a certain number of variables, I would have used:
Code:
while ( fscanf(input, "%lf %lf
", &col_1[], &col_2[]) == 2 )
{
no_rows++;
}
The problem is I want to allocate "no_rows" as the array size, which I don't have until after I have read the file.
I call a function that returns a string, and I can print it out fine, but I want to test the result of the function to see if it returns 0. But I can't just call the function again (GetNextToken(b)) because it will generate a different token. I can't allocate space for the string because I'm not sure what the size of the returned string is going to be.
Basically I want to see if the GetNextToken(b) returns 0, and if it doesn't then print the string. And running GetNextToken(b) again will give a different result.
Code:
int main(int argc, char **argv) {
SomeStruct* b = CreateStruct(argv[1],argv[2]);
printf("HERE %s", GetNextToken(b));
I have an assignment where I am trying to get the frac bits of a IEEE number representation. The number of exp and frac bits are given as parameters from the main, but I am unsure what bit mask to use as a one-size-fits mask.
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