I would like to manually reproduce the method that authors of an article used in their research (DOI: 10.1038/s41598-017-02750-9 (Page 8. top)). It is mentioned as "ACF", so I wrote different functions:
1, a version based on a youtube video (https://youtu.be/ZjaBn93YPWo?t=417) using Alglibs Pearson correlation coefficient function
2, then another version based on the formula that is described in the article mentioned above
3, then another version based on the simplified formula described at an online ACF calculator page (https://planetcalc.com/7908/)
4, then a version based on the longer formula described there (https://planetcalc.com/7908/)
=> Yet, all of these give different output. However, method 3. is consistent with the output coming from the online calculator ran in my browser: https://planetcalc.com/7884/?d=.bTkjs.ymyQ8blXMoYiMgIOOmzhhI4fnckel.J5yEDWtV89Gz32Ch0kse2s
My code is here:
#include <iostream>
#define _WIN32_WINNT 0x0500
#include<windows.h>
//#include <cmath>
#include "alglib/alglibinternal.h"
#include "alglib/alglibmisc.h"
#include "alglib/ap.h"
#include "alglib/dataanalysis.h"
#include "alglib/diffequations.h"
#include "alglib/fasttransforms.h"
#include "alglib/integration.h"
#include "alglib/interpolation.h"
#include "alglib/linalg.h"
#include "alglib/optimization.h"
#include "alglib/solvers.h"
#include "alglib/specialfunctions.h"
#include "alglib/statistics.h"
#include "alglib/stdafx.h"
using namespace std;
double* normalize(double* _arr, int _s) {
double* output = new double[_s];
double mod = 0.0;
for (size_t i = 0; i < _s; ++i)
mod += _arr[i] * _arr[i];
double mag = sqrt(mod); //TODO: if 0, throw exc
double mag_inv = 1.0 / mag;
for (size_t i = 0; i < _s; ++i)
output[i] = _arr[i] * mag_inv;
return output;
}
void doACFyoutube(double* _ina, int _s)
// https://youtu.be/ZjaBn93YPWo?t=417 => the most unefficient, but understandable method
{
double* temp_x;
double* temp_y;
double* ACFoutput = new double[_s];
for(int shift = 0; shift < _s; shift++)
{
temp_x = new double[_s-shift];
temp_y = new double[_s-shift];
for(int cpy = 0; cpy < _s-shift; cpy++)
{
temp_x[cpy] = _ina[cpy];
temp_y[cpy] = _ina[cpy+shift];
}
temp_y = normalize(temp_y, _s-shift); //not sure if needed //TODO: leak
alglib::real_1d_array temp_x_alglib;
alglib::real_1d_array temp_y_alglib;
temp_x_alglib.setcontent(_s-shift, temp_x);
temp_y_alglib.setcontent(_s-shift, temp_y);
ACFoutput[shift] = alglib::pearsoncorr2(temp_x_alglib, temp_y_alglib); //Pearson product-moment correlation coefficient
delete temp_x;
delete temp_y;
}
for(int i=0; i<_s; i++)
cout << " lag = " << i << "\tACF(lag) = " << ACFoutput[i] << endl;
}
void doACFgoal(double* _ina, int _s)
// DOI: 10.1038/s41598-017-02750-9 => page 8, first equation (my goal is to reproduce this)
{
double mean = 0; //mean
for(int a = 0; a < _s; a++ )
mean += _ina[a];
mean /= _s;
double var = 0; //variance
for(int b = 0; b < _s; b++ )
var += (_ina[b]-mean)*(_ina[b]-mean);
var /= _s-1; //needed? (-1) a.k.a. Bessell's correction ?
double* ACFoutput = new double[_s];
for(int i = 0; i < _s; i++)
{
double temp_sum = 0;
for(int j = 1; j <= _s-i; j++)
temp_sum += (_ina[j]-mean)*(_ina[j+i]-mean);
ACFoutput[i] = (double)1/(((double)_s-(double)i)*var*var) * temp_sum;
}
for(int i=0; i<_s; i++)
cout << " lag = " << i << "\tACF(lag) = " << ACFoutput[i] << endl;
}
void doACFplanetcalcCoarse(double* _ina, int _s)
// https://planetcalc.com/7908/
{
double mean = 0; //mean
for(int a = 0; a < _s; a++ )
mean += _ina[a];
mean /= _s;
double* ACFoutput = new double[_s];
for(int i = 0; i < _s; i++)
{
double temp_sum1 = 0;
double temp_sum2 = 0;
for(int j = 0; j < _s-i; j++)
temp_sum1 += (_ina[j]-mean)*(_ina[j+i]-mean);
for(int k = 0; k < _s; k++)
temp_sum2 += (_ina[k]-mean)*(_ina[k]-mean);
ACFoutput[i] = temp_sum1 / temp_sum2;
}
for(int i=0; i<_s; i++)
cout << " lag = " << i << "\tACF(lag) = " << ACFoutput[i] << endl;
}
void doACFplanetcalcFine(double* _ina, int _s)
// https://planetcalc.com/7908/ => gives different output than the online calculator script, even though uses the longer formula described there
{
double* ACFoutput = new double[_s];
for(int k = 0; k < _s; k++)
{
double mean1 = 0; //mean of first N-k values
for(int a = 0; a < _s-k; a++ )
mean1 += _ina[a];
mean1 /= _s-k;
// cout << "\t mean of first N-" << k << " values = " << mean1 << endl;
double mean2 = 0; //mean of last N-k values
for(int a = k; a < _s; a++ )
mean2 += _ina[a];
mean2 /= _s-k;
// cout << "\t mean of last N-" << k << " values = " << mean2 << endl;
double temp_sum1 = 0;
double temp_sum2 = 0;
double temp_sum3 = 0;
for(int i = 0; i < _s-k; i++)
{
temp_sum1 += (_ina[i]-mean1)*(_ina[i+k]-mean2);
// cout << "\t\t temp_sum1 (" << i << ") = " << temp_sum1 << endl;
}
// cout << "\t temp_sum1 = " << temp_sum1 << endl;
for(int i = 0; i < _s-k; i++)
{
temp_sum2 += (_ina[i]-mean2)*(_ina[i]-mean2); //pow2
// cout << "\t\t temp_sum2 (" << i << ") = " << temp_sum2 << endl;
}
// cout << "\t temp_sum2 = " << temp_sum2 << endl;
for(int i = 0; i < _s-k; i++)
{
temp_sum3 += (_ina[i+k]-mean2)*(_ina[i+k]-mean2); //pow2
// cout << "\t\t temp_sum3 (" << i << ") = " << temp_sum3 << endl;
}
// cout << "\t temp_sum3 = " << temp_sum3 << endl;
ACFoutput[k] = temp_sum1 / (sqrt(temp_sum2)*sqrt(temp_sum3));
}
for(int i=0; i<_s; i++)
cout << " lag = " << i << "\tACF(lag) = " << ACFoutput[i] << endl;
}
int main()
{
//fullscreenhez
HWND hWnd = GetConsoleWindow();
ShowWindow(hWnd,SW_SHOWMAXIMIZED);
double ina[15] = {2,3,4,5,4,3,4,5,6,7,6,5,4,3,4}; //15 elem
for(int x=0; x<15; x++)
cout << ina[x] << ",";
cout << endl;
cout << endl;
// https://youtu.be/ZjaBn93YPWo?t=417 => the most unefficient, but understandable method
doACFyoutube(ina, 15); // ??? result doesn't match any other
cout << endl;
// DOI: 10.1038/s41598-017-02750-9 => page 8, first equation (my goal is to reproduce this)
doACFgoal(ina, 15); // ??? result doesn't match any other
cout << endl;
// https://planetcalc.com/7908/ (simplified formula)
doACFplanetcalcCoarse(ina, 15); //result equals to the online calculator result: https://planetcalc.com/7884/?_d=.bTkjs.ymyQ8blXMoYiMgIOOmzhhI4fnckel.J5yEDWtV89Gz32Ch0kse2s_
cout << endl;
// https://planetcalc.com/7908/ (longer formula)
doACFplanetcalcFine(ina, 15); // ??? result doesn't match any other
return 0;
}
The output looks like this:
As I do not have the original data they used in the publication, I can only rely on how consistent the output of my program is related to other codes output. But these outputs are different, and I do not know why. Could you please have a look at the code and help me end up in four equal outputs?
(Codeblocks project zipped here:
https://drive.google.com/file/d/1s3SeJSiDgk-hiMazp94HfFerL582VG2K/view?usp=sharing)
I'm doing my os homework, and the requirement is to implement parallel merge sort using Pthread and using semaphore to lock and unlock them.
You can only look at the function names Multi____ and ignore Single_____, because I've already finished the single thread part.
I encountered a problem in the multithreaded part. I signal the master thread (sem[1]) in line 227, and it should go into the function 'void *MultiPartition'.
In this function, it gives value to arg[id * 2] and arg[id * 2 + 1].
For example, arg[1] will gives value to arg[2] and arg[3], and then it signals thread[2] and thread[3] to start by sem_post.
And doesn't seem to work.
So I use cout << "partition id = " << id << ", head = " << head << ", mid = " << mid << ", tail = " << tail << "\n"; in line 111 to check out what happens.
It looks really weird. It sometimes outputs
partition id = 1, head = 0, mid = 7, tail = 15
partition id = 2, head = 0, mid = 3, tail = 7
and it was stuck, but the program didn't exit. Means I need to press Ctrl^C to exit program.
Sometimes it outputs
partition id = 1, head = 0, mid = 7, tail = 15
partition id = 2, head = 0, mid = 3, tail = 7
partition id = 3, head = 8, mid = 11, tail = 15
partition id = 4, head = 0, mid = 1, tail = 3
and was stuck, too.
I'm curious where other threads going?
And if id = 4 is displayed, it will runs bubble id = 8 usually.
#include <iostream>
#include <pthread.h>
#include <semaphore.h>
#include <fstream>
#include <sys/time.h>
#include <unistd.h>
using namespace std;
//Pthread_create, pthread_exit *don't use pthread_join
//sem_init, sem_wait, sem_post, sem_getvalue, sem_destroy
//Enter input file name: test.txt
//MT sorting used x secs
//ST sorting used x secs
// g++ -o os_hw3.out os_hw3.cpp -pthread
typedef struct{
int head;
int mid;
int tail;
int id;
}arguments;
//declare global variables
sem_t sem[16]; // use id = 1 ~ 15
sem_t final; // the final semaphore signal that indicate all threads finished.
int* s1, * s2; // two array for single and multiple
arguments arg[16];
void swap(int* x, int* y) {
int temp;
temp = *x;
*x = *y;
*y = temp;
}
void *MultiMerge(void* argid) {
int id = *(int*)argid;
sem_wait(&sem[id]);
sem_wait(&sem[id]);
int head = arg[id].head, mid = arg[id].mid, tail = arg[id].tail;
//cout << "merge id = " << id << ", head = " << head << ", mid = " << mid << ", tail = " << tail << "\n";
int lenA = mid - head + 1;
int lenB = tail - (mid + 1) + 1;
int A[lenA];
int B[lenB];
for (int i = 0; i < lenA; i++) {
A[i] = *(s1 + head + i);
}
for (int j = 0; j < lenB; j++) {
B[j] = *(s1 + mid + 1 + j);
}
int i = 0, j = 0, k = 0;
while (i < lenA && j < lenB) {
if (A[i] < B[j]) {
*(s1 + head + k) = A[i];
i++;
}
else {
*(s1 + head + k) = B[j];
j++;
}
k++;
}
while (i < lenA) {
*(s1 + head + k) = A[i];
i++;
k++;
}
while (j < lenA) {
*(s1 + head + k) = B[j];
j++;
k++;
}
sem_post(&sem[id / 2]); // signal the upper level
if (id == 1) {
fstream fout;
fout.open("output1.txt", ios::out);
for (i = 0; i < arg[1].tail + 1; i++)
fout << *(s2 + i);
fout.close();
sem_post(&final);
}
}
void *MultiBubble(void *argid) {
int id = *(int*)argid;
sem_wait(&sem[id]);
//cout << "bubble id = " << id << ", head = " << arg[id].head << ", tail = " << arg[id].tail << "\n";
for (int i = arg[id].tail; i > 0; --i) {
for (int j = arg[id].head; j < i; ++j) {
if (*(s2 + j) > * (s2 + j + 1)) {
swap((s2 + j), (s2 + j + 1));
}
}
}
for (int i = arg[id].head; i <= arg[id].tail; i++) {
cout << *(s2 + i) << " ";
}
cout << "\n";
sem_post(&sem[id / 2]);
}
void *MultiPartition(void* argid) {
int id = *(int*)argid;
sem_wait(&sem[id]);
int head = arg[id].head, mid = arg[id].mid, tail = arg[id].tail;
cout << "partition id = " << id << ", head = " << head << ", mid = " << mid << ", tail = " << tail << "\n";
arg[id * 2].head = arg[id].head;
arg[id * 2].tail = arg[id].mid;
arg[id * 2].mid = (arg[id * 2].head + arg[id * 2].tail) / 2;
arg[id * 2 + 1].head = arg[id].mid + 1;
arg[id * 2 + 1].tail = arg[id].tail;
arg[id * 2 + 1].mid = (arg[id * 2 + 1].head + arg[id * 2 + 1].tail) / 2;
sem_post(&sem[id * 2]);
sem_post(&sem[id * 2 + 1]);
}
void SingleMerge(int* s1, int head, int mid, int tail) {
int lenA = mid - head + 1;
int lenB = tail - (mid + 1) + 1;
int A[lenA];
int B[lenB];
for (int i = 0; i < lenA; i++) {
A[i] = *(s1 + head + i);
}
for (int j = 0; j < lenB; j++) {
B[j] = *(s1 + mid + 1 + j);
}
int i = 0, j = 0, k = 0;
while (i < lenA && j < lenB) {
if (A[i] < B[j]) {
*(s1 + head + k) = A[i];
i++;
}
else {
*(s1 + head + k) = B[j];
j++;
}
k++;
}
while (i < lenA) {
*(s1 + head + k) = A[i];
i++;
k++;
}
while (j < lenA) {
*(s1 + head + k) = B[j];
j++;
k++;
}
}
int SingleBubble(int* s1, int head, int tail) {
for (int i = tail; i > 0; --i) {
for (int j = head; j < i; ++j) {
if (*(s1 + j) > *(s1 + j + 1)) {
swap((s1 + j), (s1 + j + 1));
}
}
}
}
void SinglePartition(int* s1, int head, int tail, int times) {
if (head <= tail) {
int mid = (head + tail) / 2;
if (times < 3) {
SinglePartition(s1, head, mid, ++times);
SinglePartition(s1, mid + 1, tail, ++times);
}
else {
SingleBubble(s1, head, tail);
}
SingleMerge(s1, head, mid, tail);
}
}
int main() {
char filename[100];
int num;
struct timeval Tstart, Tend;
cout << "Enter the input file name: ";
cin >> filename;
fstream file, fout;
file.open(filename, ios::in);
if (!file) {
cout << "Read File Error.\n";
return -1;
}
else {
file >> num;
s1 = new int[num];
s2 = new int[num];
for (int i = 0; i < num; i++) {
file >> *(s1 + i);
*(s2 + i) = *(s1 + i);
}
file.close();
}
//SINGLE THREAD
gettimeofday(&Tstart, 0);
SinglePartition(s1, 0, num - 1, 0);
gettimeofday(&Tend, 0);
fout.open("output2.txt", ios::out);
for (int i = 0; i < num; i++)
fout << *(s1 + i) << " ";
fout.close();
double Tdifference = (Tend.tv_sec - Tstart.tv_sec) + (Tend.tv_usec - Tstart.tv_usec) / 1000000.0;
cout << "Single thread cost " << Tdifference << " s\n";
//MULTI THREAD
gettimeofday(&Tstart, 0);
arg[1].head = 0;
arg[1].tail = num - 1;
arg[1].mid = (arg[1].head + arg[1].tail) / 2;
pthread_t thread[16];
sem_init(&final, 0, 0);
sem_post(&sem[1]);
for (int i = 1; i < 16; i++){
arg[i].id = i;
sem_init(&sem[i], 0, 0);
if (i < 8) {
if(i == 1)
sem_post(&sem[1]); // call the master thread
pthread_create(&thread[i], NULL, MultiPartition, &arg[i].id);
}
else
pthread_create(&thread[i], NULL, MultiBubble, &arg[i].id);
}
for (int i = 7; i > 0; i--) {
pthread_create(&thread[i], NULL, MultiMerge, &arg[i].id);
}
sem_wait(&final);
gettimeofday(&Tend, 0);
Tdifference = (Tend.tv_sec - Tstart.tv_sec) + (Tend.tv_usec - Tstart.tv_usec) / 1000000.0;
cout << "Multi thread cost " << Tdifference << " s\n";
delete s1, s2;
for (int i = 0; i < 16; i++)
sem_destroy(&sem[i]);
sem_destroy(&final);
return 0;
}
I fixed it myself.
for (int i = 7; i > 0; i--) {
pthread_create(&thread[i], NULL, MultiMerge, &arg[i].id);
}
The above part will confront the following part.
for (int i = 1; i < 16; i++){
arg[i].id = i;
sem_init(&sem[i], 0, 0);
if (i < 8) {
if(i == 1)
sem_post(&sem[1]); // call the master thread
pthread_create(&thread[i], NULL, MultiPartition, &arg[i].id);
}
MultiMerge and MultiPartition both have
sem_wait(&sem[id]);
So if sem[id]'s value != 0, it doesn't know which function to do, in my opinion.
I delete
for (int i = 7; i > 0; i--) {
pthread_create(&thread[i], NULL, MultiMerge, &arg[i].id);
}
and add
MultiMerge(&arg[id].id);
in the bottom of MultiPartition to call MultiMerge, this can fixed my problem.
I have difficulties in solving this problem. I try to write a program that shows how many times every character occurs in sentence.
For example: ,,hello"
h-1 times
e-1 times
l-2 times
o-1 times
here is my idea:
char sentence[100] = "";
cin.getline(sentence, 100);
char letters[100] = "";
int counter = 0;
for (int i = 0; i < strlen(sentence); i++) {
cout << sentence[i] << endl;
letters[i] = sentence[i];
}
for (int i = 0; i < strlen(sentence); i++) {
for (int j = 0; j < strlen(sentence); j++) {
if (letters[j]==sentence[i]) {
counter++;
cout << letters[j] << " occurs " << counter << " in the sentence" << endl;
}
}
}
but my counter doesn't work correctly and I don't know how to fix it.
put counter = 0 in each iteration of cycle:
for (int i = 0; i < strlen(sentence); i++) {
counter = 0
for (int j = 0; j < strlen(sentence); j++) {
if (letters[j]==sentence[i]) {
counter++;
cout << letters[j] << " occurs " << counter << " in the sentence" << endl;
}
}
}
It is work, but better and simply using map:
char sentence[100] = "";
cin.getline(sentence, 100);
map<char, int> counter;
int len = strlen(sentence);
for (int i = 0; i < len; i++){
counter[sentence[i]]++;
}
for (map<char,int>::iterator it = counter.begin(); it != counter.end(); it++){
cout << it->first << " occurs " << it->second << " in the sentence" << endl;
}
for this you should #include <map>
I'm trying to create a program that will check if a given number (between 1 and 1000) is prime but ran across a problem or two. The code I have below will run, but output 1000 times because of line 14 (for(int i = 3; i <= ELEMENTS; i++){) I know why it's running 1000 times but I can't find a way around it.
#include<iostream>
using namespace std;
int main(){
cout << "enter number of interest: ";
int num;
cin >> num;
const int ELEMENTS =1000;
bool multiples[ELEMENTS] = {};
for(int i = 3; i <= ELEMENTS; i++){
for(int j = 2; j <= i - 1; j++){
multiples[i]=true;
if(i % j == 0){
multiples[j]=false;
}
}
if((multiples[num] == true)){
cout << num << " is prime" << endl;
}
else
cout <<num<< " is not prime"<<endl;
}
return 0;
}
Move it out of for loop. Since variables it uses are defined out of for loop scope, it will work fine.
Edit: correct fragment:
for(int i = 3; i <= ELEMENTS; i++){
for(int j = 2; j <= i - 1; j++){
multiples[i]=true;
if(i % j == 0){
multiples[j]=false;
}
}
}
if (multiples[num] == true) {
cout << num << " is prime" << endl;
}
else
cout << num << " is not prime" << endl;
My code compiles but throws the following exception:
An unhandled exception of type 'System, Access Violation Exception' occured Additional Information: Attempted to read or write protected memory. . .
the error is related to s=s+a[z][r]*b[f][h]
Here a copy of the code:
#include"stdafx.h"
#include"iostream"
using namespace std;
int main()
{
int **a, **b;
int z, r, f, h, a_r, a_c, b_r, b_c, s = 0;
cout << "Enter the size of the matrix(nxm) :" << endl;
cin >> a_r >> a_c;
cout << "enter the size of the mask :" << endl;
cin >> b_r >> b_c;
a = (int **) malloc(10 * a_r);
for (int i = 0; i < a_c; i++)
{
a[i] = (int *) malloc(10 * a_c);
}
b = (int **) malloc(10 * b_r);
for (int i = 0; i < b_c; i++)
{
b[i] = (int *) malloc(10 * b_c);
}
for (int i = 0; i < a_r; i++)
{
for (int j = 0; j < a_c; j++)
{
a[i][j] = i + j;
}
}
for (int i = 0; i < b_r; i++)
{
for (int j = 0; j < b_c; j++)
{
b[i][j] = i + j;
}
}
int k = 1, d = 1;
for (int i = 0; i < a_r; i++)
{
for (int j = 0; j < a_c; j++)
{
for (int n = -1; n <= 1; n++)
{
for (int e = -1; e <= 1; e++)
{
z = i + n;
r = j + e;
f = k + n;
h = d + e;
if (z < 0 || z > a_r || r < 0 || r > a_c)
{
s = s + 0;
} else {
s = s + a[z][r] * b[f][h]; // runtime error occurs here
}
}
}
a[i][j] = s;
s = 0;
}
}
return 0;
}
Here is one problem:
if (z < 0 || z > a_r || r < 0 || r > a_c)
This should read:
if (z < 0 || z >= a_r || r < 0 || r >= a_c)
Otherwise you're potentially accessing out-of-bounds elements.