C :: Saving Matrices With Data Structures?
Dec 4, 2014
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;
}
[Code]....
View 7 Replies
ADVERTISEMENT
Jul 18, 2014
I am receiving packets of data from an ethernet cable. This is the line of code that is streaming in data from the ethernet cable:
size_t num_rx_samps = rx_stream->recv(&buff.front(), buff.size(), md, 3.0, enable_size_map);[code]
Here are the segments of me trying to push the packets onto a vector:
[code]
std::vector<size_t> processing_queue; //HERE IS WHERE I'M TRYING TO PUSH THE PACKETS ONTO A VECTOR
processing_queue.push_back(num_rx_samps);
[code]
I previously had my program saving to a .dat file (the commented out lines), but I need to change it to pushing values onto a vector so I can stream the data packets from the ethernet cable to be processed. However, the packets aren't being pushed onto the stack as I suspected. What do I need to change to push the data packets onto a vector? The following is the code:
[code]
#include <uhd/types/tune_request.hpp>
#include <uhd/utils/thread_priority.hpp>
#include <uhd/utils/safe_main.hpp>
#include <uhd/usrp/multi_usrp.hpp>
#include <uhd/exception.hpp>
#include <boost/program_options.hpp>
[code]....
View 1 Replies
View Related
Sep 13, 2013
I have a problem when i try to save unicode to a .txt file.
I need to store in a file names that will have letters like "ăĂâÂșȘțȚîÎ"
wchar_t name []=L"ăĂâÂșȘțȚîÎ";
FILE* fang;
fang= _wfopen( L"test.txt",L"wt+,ccs=UNICODE");
fwprintf (fang, L"%ls ",name);
When i open my text file i get this: ??âÂ????îÎ
if i use
fang=fopen("test.txt","a");
I get the same result
and for
fang=fopen("ang.txt","a,css=UNICODE");
I get a runtime eroror "invalid file open mode"
View 2 Replies
View Related
Dec 4, 2013
I have a program that saves all information temporarily into memory (into the array), however, I need a permanent save solution. I have the full program working correctly, formatted perfectly, but it's missing the file array to file output.
Essentially, whenever I'm presented with the menu I'll be able to add entries, search by last name, show the entire list, and exit and save. Whenever I select option 4 the program should save to a file "address_book.txt". Whenever I reload the program, it should load from "address_book.txt" and populate the array with the preexisting data.
My question is focused on how and where I should implement the file output. What I have thus far:
#include <iostream>
#include <string.h> //Required to use string compare
#include <fstream> //Eventually used to store array into file
using namespace std;
class AddBook{
[Code] ....
View 5 Replies
View Related
Mar 17, 2014
I want to connect an access database (.mdb) to my Windows Forms application - this I can do and I have no problems viewing my table in server explorer.
Some code example or template that I can use as a base to learn from - I have literally trawled Google and Youtube and cannot find what I am after.
What I want to do is have a basic form, 2 text boxes and a button to save the data to my database.
FirstName and LastName are the 2 boxes.
View 6 Replies
View Related
Jan 6, 2015
I need to save RGB values of each pixel in a 3D array A[width][height][3]. I found a code online that transfers the bytes into an array but I cant understand how bytes are saved them so i could transfer them into an array. The truth is I dont know much about working with images at all so i have a problem working on them. How to transfer the RGB data from an .jpeg image into a 3D array? This is my code so far:
#include <iostream>
#include <jerror.h>
#include <jpeglib.h>
using namespace std;
int main(){
FILE *pic = fopen( "image.jpeg", "rb+" );
[Code] .....
View 6 Replies
View Related
Jul 18, 2013
I am working on a project that uses a web service to extract a PNG image from a web server and save it on a local machine. It's done via a system call. I can get the output of the system call to a FILE but it appears to be losing data, most notably the PNG chunk names (IHDR/PLTE/IDAT/IEND, notably). (Unfortunately piping the output to an exterior file does not work through a system call.) The end result is ~6KB smaller than the file I am intending to retrieve.
This is the code I'm using (adapted from other material I found via searches here):
ofstream png;
png.open(/*outputfile*/, ios::binary);
FILE* fp = _popen(/*SYSTEMCALL*/, "rb");
string responseString;
if(fp != NULL) {
char a[100];
while(!feof(fp)) {
fgets(a, 100, fp);
responseString += a;
}
}
_pclose(fp);
png << responseString;
Am I missing something or just doing it wrong?
View 11 Replies
View Related
May 18, 2014
I would like to create program which will analyse bitmap so would need good concept to save data. I am interested about the theory and I realize that i must to think this carefully because bad concept could create insufficient memory or inefficient program. Basically I want my program work with HSV or HSL model so I would need to convert the bitmap to HSL, but I am not sure if I should convert it first and then analyse all pixels or should I start to analyse the bitmap and make the conversion to HSL during it. But my main question is what method to choose to save the data in memory.
Even that I would start with very small, it should work also with bigger image like image having 1200 or even 4200 px on height. So the program should first analyse all columns of pixels in the image so for example 1200x800 px image has 1200 columns. So I would like to know if is it possible to create such object which would have such structure like this
Obj->basicColumnData->black->columns[name]->group
and in the place of columns should be placed data for every column. I would look for groups of pixels in the column, so in the result the column x could bear e.g. 500 groups of information and every group should contain the range of pixels e.g. group 1 should contain y value from 0 to 20, group 2 should contain value from 25-27 and so on. So I would create 1200 columns bear many of groups. This would be contained in "black" or "white" member to contain the data. This is just simplified idea, but the whole object should contain next data not just basicColumnData... So there should be another members bearing information calculated from the selected data.
So my question is what kind of method of saving data use for this? Should I use heap and dynamic allocated memory or should I create custom class, which will define every member, but these members will have to be dynamic memory? With the dynamic memory is there problem that there could be not enough memory to create such big object?
View 5 Replies
View Related
Jun 1, 2013
I have an application with general customer detail.
It has TextBox and radio button.
First I have used if statement then code but on first step is working fine then error is showing.
try
{
if (textBox1.Text == "")
{
[Code].....
View 5 Replies
View Related
Jul 2, 2014
I created one structure and the created structure is using in few more structures, but i did not get the proper data.
typedef struct _MSG_HEADER{
//MESSAGE_HEADER 40 bytes
short iApiTcode;
short iApiFuncId;
int LogTime;
char AlphaChar[2];
[Code]...
My requirement is have to fill the MessageHeader structure & we can use that header in all the structures entire program.
View 3 Replies
View Related
Nov 2, 2014
I'm reading the following file:
Osgood,Marcus 298542123 CHM FR mosgood@whatever.edu
Cronk,Melissa 873489021 BIO SR mcronk@whatever.edu
Pry,Seth 349908431 MTH SO spry@whatever.edu
Langlais,Susan 783323545 ME SR slanglais@whatever.edu
Davis,Nicole 987543345 PHY FR ndavis@whatever.edu
It's supposed to split it up into name, ID number, major, year, and email. The file reads it without any errors, and assigns name to the first part of the structure. However, ID gets assigned the ID, major, year, and email. Then Major gets assigned major, year, and email. Year gets assigned year and email, while email just gets assigned email. I don't know if it has something to do with the loop. For example, this is what I get what I print just the name and the ID.
Cronk,Melissa 873489021BIOSRmcronk@whatever.edu
Pry,Seth 349908431MTHSOspry@whatever.edu
Langlais,Susan 783323545ME
Davis,Nicole 987543345 PHYFRndavis@whatever.edu
Anyway. This is my function code for reading the array. I have it printing the ID number just to see if I can catch the errors earlier:
Code:
#include <stdio.h>
#include <string.h>
#include "functions.h"
void read_data(char filename[], studentinfo_t s[], int *size) {
FILE *infilep;
int countstudents = 0;
infilep = fopen("student_data", "r");
[Code].....
the name is reading correctly, but not anything else!
View 1 Replies
View Related
Oct 26, 2013
I need an explanation of what linked lists are. How the nodes are been defined and used, especially in an object oriented programming. With a code example.
View 1 Replies
View Related
Feb 17, 2013
I want to have input data stored in a database. All information entered is to be stored under a single block. That way whenever I want to recover that information all I have to do is point to that block. Think of it like this. I want a large square block that can hold certain information. Inside of that large block are a finite amount of smaller blocks in which the user entered information about a single subject. Lets say block 1 has a name, address, and phone number. The second block will have the same TYPE of information, but different values as entered by the user. I.E:
BLOCK 1: Name 1, Address 1, Phone 1
BLOCK 2: Name 2, Address 2, Phone 2
etc.
The large block contains all of the smaller blocks, we will name the large block "Address Book" ... How would I implement that? Of course it would be just a simple console program that would erase all information when the program shut down, but I've been trying to figure out how to do it, but just can't seem to grasp a good notion of how to do it. What would be the best way to do that? Structures? How would I make it dynamic so that I wouldn't have to define every block, so that it would be added on the fly when someone inputs new information.
View 2 Replies
View Related
Apr 16, 2014
We're writing a program in class using data structures and arrays and I'm stuck on writing a loop to find the students' highest test score. I only return the first student's ID, test score, and grade. For some reason unknown to me I'm not actually looping through all 12 or so records.
Code:
#include <stdio.h>
#define MAX_ENTRIES 50
struct records
{ //declare my student records structure
int ID; //the student's ID number
int test_score; //the student's test score
char grade; //the student's letter grade of aforementioned test score
};
[code]....
View 5 Replies
View Related
Sep 26, 2014
typedef struct example_dt_struct {
int a;
float b;
char* c;
};
typedef void(*func)(example_dt_struct *s, int e, int f);
void f(func *n){}
how can i use example_dt_structure with my function pointer into f()
View 5 Replies
View Related
Feb 3, 2014
So this makes an output of the head (a square), and the leg (rectangle. How do I make my points into a data structure in the shortest yet simplest way possible?
#include <vector>
#include <time.h>
using namespace std;
#include "Glut_Setup.h"
float
head1x= -0.5, head1y=3, head1z=0,
head2x= 0.5, head2y=3, head2z=0,
head3x= 0.5, head3y=2, head3z=0,
head4x= -0.5, head4y=2, head4z=0;
[Code] .....
View 10 Replies
View Related
Feb 27, 2014
So I made a code that shows a simple rectangle. How do I make it move using data structures? :)
Code:
#include "Glut_Setup.h"
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <vector>
#include <time.h>
using namespace std;
float P1= -5;
float P2= 2;
[Code] .....
View 2 Replies
View Related
Apr 8, 2014
I am trying to read the information from a .bmp file into my program while dynamically allocating memory for all of it. So I defined the structures for the headers and for a pixel, and then I have to read each pixel into a multi-dimensional array of pixels. I am completely new to structures, and definitely new to pointers combined with structures. I will have to use a filter with the information later, but right now I just want to read everything in correctly. The array of pixels will be two-dimensional -- the width by the height of the image, I guess.
Here's my code:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char *argv[]) {
FILE *inFile, *outFile;
typedef struct
[Code] ....
View 4 Replies
View Related
Jun 9, 2014
Why certain projects always roll their own data structures/utililiy classes rather than using the C++ standard libraries? such as linked lists and queues? Is there a particular reason for this?
View 11 Replies
View Related
Mar 30, 2014
The program use a circular linked list and data structures to store the tasks.
- Every task should include a task name, a name for the person assigned to it, and the deadline for the task.
- Variables should be dynamic and their sizes should be determined at runtime based on the length of user input.
- You should implement the following functions (with appropriate arguments and return types) for your structure: add(), remove(), search(), and list().
- The add()function should add tasks alphabetically by task name. You do not need to implement any file operations.
- The search() function should be able search for a task by the task assignee name or the task name.
- The list() function should print records to the screen in the order they appear in the circular linked list.
- You should successfully deallocate all of the allocated memory before termination of your program.
View 4 Replies
View Related
Nov 26, 2014
// my size is not decreasing when I erase a record.
//dvr_hwch.cpp
#include <iostream>
#include <iomanip>
#include <cassert>
using namespace std;
#include "hash_chn.h"
void print_menu( );
[Code] .....
View 1 Replies
View Related
May 13, 2012
I am trying to read from a data file that has input as :
12.0, 11, 123
14.0, 12.1, 3
And I want the program to read the data from the file and then make it into an array of structures and then print that array afterwards.
Code:
#include <stdio.h>
#include <stdlib.h>
#define MAX_INPUT 1000
int n =0;
int i = 0;
typedef struct {
double x[MAX_INPUT];
[Code] .....
The program when run gives the following output:
Ishtiaque-Mohammed-Khans-MacBook-Pro:Comp20005 IshtiaqueMKhan$ gcc -Wall -ansi -o ProjectB ProjectB.c
ProjectB.c: In function "main":
ProjectB.c:59: error: incompatible type for argument 1 of "print_array"
View 1 Replies
View Related
Dec 11, 2013
I am writing a employee payroll program using structures. My program is running but its only showing some of the data.
HERES MY CODE
Code:
#include <iostream>
#include <cstdio>
#include <fstream>
#include <string>
#include <iomanip>
#include <cstring>
using namespace std;
const int SZ = 20; // size of arrays to hold scores
struct payrollStruct {
[Code] ....
And it doesn't show anything from txt file
Code:
40.0 10.00 A1234 Jane Adams
50.0 10.00 L8765 Mary Lincoln
25.5 10.85 W7654 Martha Washington
52.0 15.75 A9876 John Adams
45.0 25.00 W1235 George Washington
[Code] .....
View 14 Replies
View Related
Dec 4, 2013
I have a program that stores health information the user inputs, one person at a time. The program works perfectly with the exception of storing the data...I need to open a file and read what health data it has in it already, if any, but store the new changes, and appended data to the array of structures, to the data in memory. All of the information is only saved back in the file once the program terminates. I'm not sure how to go about doing this, so I am also not sure what to put in the function for "Save and Exit" that the user can choose in order to exit the program.
Code:
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
struct strdatabase
{
char first[20];
char last[20];
char gender[2];
[Code]...
I tried playing around with this bit of code, but I'm not sure if I'm even on the right track.
Code:
FILE *fp;
fp = fopen ("students.txt","rb"); fseek(fp, 0, SEEK_END);
long pos = ftell(fp);
fseek(fp, 0, SEEK_SET);
char *bytes = malloc(pos);
fread(bytes, pos, 1, fp);
fclose(fp);
View 9 Replies
View Related
Mar 6, 2013
How do you add two matrices together ?
View 2 Replies
View Related
Mar 7, 2014
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
Attached image(s)
View 11 Replies
View Related
