index out of range problem

[Jimmy01901]

I have problem with my c++ program which is connected with qml. I'm trying to add values from QVector to QVariantList(because this type is needed in BarSeries in qml etc.) in for loop. I was adding some cout<< to see where the problem is located, but only what I discovered that my for loop is repeat 8 times with this loop conditions (int i = 0; i<5;i++). My problem is: ASSERT failure in QVector::operator[]: "index out of range" and it is linked to file in which I can see this:{ Q_ASSERT_X(i >= 0 && i < d->size, "QVector::operator[]", "index out of range"); return data()[i]; }

I also add and to my cpp files. Whole the code is working, only last function doesn't. Here's my code, Transformacja.h:

#include <QObject>
#include <fftw3.h>
#include <iostream>
#include <QVariant>
#include <QVariantList>
using namespace std;

#define Re 0
#define Im 1
#define PI 3.14159265359

class Transformacja : public QObject {
    Q_OBJECT
public:
    Q_INVOKABLE static void wykonaj(QVector<double> sygnal);
public:
    static int N;
    static QVector<double> A;
    static QVector<double> procenty;

    Q_INVOKABLE static QVector<double> get_A();
    Q_INVOKABLE static int get_N();
    Q_INVOKABLE static QVector<double> get_procenty();
    Q_INVOKABLE static QVariantList wektor_lista();
    //const QVector<double>& vector
};

Transformacja.cpp:

#include <cmath>
#include <Transformacja.h>
#include <QList>
#include <QVariant>
#include <QVariantList>

QVector<double> Transformacja::A;
int Transformacja::N;
QVector<double> Transformacja::procenty;


void Transformacja::wykonaj(QVector<double> sygnal)
{
    Transformacja::N = sygnal.size(); //okreslenie ilosci probek

    //cout<<"ilosc probek: "<<ilosc_probek<<endl;
    //cout<<"Re: "<<Re<<endl;
    //cout<<"Im: "<<Im<<endl;

    fftw_complex *T = (fftw_complex*)fftw_malloc(Transformacja::N * sizeof(fftw_complex)); //tablica zespolona PO transformacie
    fftw_complex *U = (fftw_complex*)fftw_malloc(Transformacja::N * sizeof(fftw_complex)); //tablica sygnalu przed transformata



    for(int i=0;i<Transformacja::N;i++)  //zamiana sygnal na fftw_complex U
    {
        U[i][Re] = sygnal[i];
        U[i][Im] = 0;
        //cout<<i+1<<". U zespolone: "<<U[i][Re]<<"+j"<<U[i][Im]<<endl;
    }


    fftw_plan plan = fftw_plan_dft_1d(Transformacja::N,U,T,FFTW_FORWARD,FFTW_ESTIMATE); //fftw plan czyli deklaracja jak to zrobic, ile razy, z jakiej tablicy, do jakiej tablicy,
    //cout<<"utworzono plan"<<endl;
    fftw_execute(plan);  // wykonanie transformaty czyli w tym miejscu T juz nie powinno byc puste
    //cout<<"wykonano plan"<<endl;
    fftw_destroy_plan(plan); //usuwanie tego planu powyzej bo wsm po co ma byc w pamieci lol
    //cout<<"usunieto plan"<<endl;
    fftw_cleanup(); //jaki cleanup czyli sprzatanie po planie
    //cout<<"wykonano cleanup"<<endl;



       //tablica X ktora ma ilosc probek
    //cout<<"utworzono X"<<endl;
    Transformacja::A.resize(Transformacja::N); //deklaracja ze bedzie ilosc probek
   // cout<<"rozszerzono X"<<endl;


    for(int i=0;i<Transformacja::N;i++) //przeliczanie transformaty na amplitudy - co to znaczy - wyswietla sie 2*|T|/ilosc probek
    {
        Transformacja::A[i] = 2.0* sqrt( pow(T[i][Re],2)+pow(T[i][Im],2)) / Transformacja::N;
        //cout<<i<<". amplituda: "<<X[i]<<endl;
    }

    //cout<<"przepisano X do QVector"<<endl;
    fftw_free(T);
    fftw_free(U);
    //cout<<"zwolniono T i U"<<endl;
    //cout<<"Wykonano pomyslnie transformate :) "<<endl;




    //to od razu z bomby robi tablice procentowa
    Transformacja::procenty.resize(Transformacja::N);
    //Transformacja::procenty[3] = 100*Transformacja::A[3]/Transformacja::A[1];
    //cout<<Transformacja::procenty[3]<<endl;
    //cout<<Transformacja::N<<endl;
    for(int i=0;i<Transformacja::N;i++)
    {
        Transformacja::procenty[i] = 100*Transformacja::A[i]/Transformacja::A[1];

        /*if(Transformacja::procenty[i]>100||Transformacja::procenty[i]<0)
        {
            cout<<i<<"ta harmoniczna ma wieksza amplitude niz podstawowa"<<endl;

        }
        else
        {

        }
        cout<<"procentowy udzial "<<i<<"tej harmonicznej:"<<Transformacja::procenty[i]<<endl;
        */
    }
}

QVector<double> Transformacja::get_A()
{
    return Transformacja::A;
}
int Transformacja::get_N()
{
    return Transformacja::N;
}
QVector<double> Transformacja::get_procenty()
{
    return Transformacja::procenty;
}

QVariantList Transformacja::wektor_lista()
{
    QVector<int> vec = {1,2,3,4,5,6};
    QVariantList lista;
    //lista.append(vec.at(1));
    //cout<<lista.size()<<endl;
    //lista.append(vec.at(2));
    //lista.append(vec.at(3));
    //for(int i=0; i<vector.size()-1; i++){
    //    lista.append(vector[i]);
    //}
    for(int i=0; i<vec.size()-1; i++){ 
        lista.append(vec[i]);
    }
    return lista;
}

in main.qml I just want to use BarSet to show percentage of harmonics in non-sinusoidal signals:

BarSeries{
    id: wykres_FFT
    axisX: axisX
    axisY: axisY
    BarSet{
        id: barset
        values: transformacja.wektor_lista()
//what i want here is values: transformacja.wektor_lista(transformacja.get_procenty()), but for now I'm trying to solve easiest problem....
    }
}

Could you see where the problem is or could you help me with some tips? Maybe more debugs or sth. Sorry for my English, I'm still learning.

[jsulm]

@Jimmy01901 You posted several loops without saying which one is causing the problem.

[sierdzio]

@Jimmy01901 run with debugger attached and it will show you exactly where the fail is.

The assert is very clear: you are trying to access an invalid index of the vector (so, index smaller than zero or equal or larger than size()). Where exactly it happens I do not know, you are accessing vector elements in many places in Transformacja::wykonaj(QVector<double> sygnal) without checking size().

Also, on an unrelated note: try to avoid programming in Polish (or any other language than English). It is very hard to understand mixed-language code. And most programming projects are international so somebody at some time will have a hard time trying to understand your code... like right now when you post it on English-speaking forum ;-) I happen to know Polish but this is just a coincidence.

[Jimmy01901]

@sierdzio okey, sory about Polish language, I’m learning programming and it’s easier for me to know „what is where”.

[Jimmy01901]

@jsulm My bad, I’m sorry, the function wektor_lista crashes my app

[jsulm]

@Jimmy01901 said in index out of range problem:

wektor_lista

I don't see anything wrong there. Please run in debugger like @sierdzio suggested to see what exactly happens.

[Chris Kawa]

@Jimmy01901 Your Transformacja::wektor_lista function leaves the last element out (note size()-1), so I'm guessing you're then accessing the list believing there's one more item than it really has.

Btw. if you just want to make a variant list out of vector elements you can do it like this:

QVector<int> vec {1,2,3,4,5,6};
QVariantList list (vec.begin(), vec.end());

Also, since vec is local anyway, why even bother with transforming it. You can just do

QVariantList Transformacja::wektor_lista()
{
   return {1,2,3,4,5,6};
}

[Jimmy01901]

@Chris-Kawa I will try this thank you