new to c++ & not sure how to solve this error? | Together C & C++ | Page 1

candid mothBOT Apr 2, 2024, 2:04 PM

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native kestrel Apr 2, 2024, 2:04 PM

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#define MATCHINGPROBLEM_H_INCLUDED

#pragma once

#include <vector>
#include <random>
#include <algorithm>
#include <iostream>
#include "GeneticAlgorithmSolver.h"

class GeneticAlgorithmSolver {
public:
    GeneticAlgorithmSolver(const MatchingProblem& problem, int populationSize, int selectionSize);

    void initialize(const std::vector<double>& lowerBounds, const std::vector<double>& upperBounds);

    void iterate();

    double getMaxParameterRange() const;

    std::vector<double> getCurrentBest() const;

private:
    const MatchingProblem& problem;
    int populationSize;
    int selectionSize;
    std::vector<std::vector<double>> population;
    std::vector<double> costs;
    std::vector<double> lowerBounds;
    std::vector<double> upperBounds;
    std::default_random_engine rng;

    void generateRandomParameters(std::vector<double>& parameters);

    void evaluatePopulation();

    void selectParents(std::vector<std::vector<double>>& parents);

    void crossover(const std::vector<std::vector<double>>& parents, std::vector<std::vector<double>>& offspring);

    void mutate(std::vector<std::vector<double>>& population);
};

#endif // MATCHINGPROBLEM_H_INCLUDED

dusky coral Apr 2, 2024, 2:04 PM

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!code

candid mothBOT Apr 2, 2024, 2:04 PM

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How to Format Code on Discord

Markup

```cpp
int main() {}
```

Result

int main() {}

dusky coral Apr 2, 2024, 2:05 PM

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How are you compiling your code?

native kestrel Apr 2, 2024, 2:06 PM

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dusky coral How are you compiling your code?

mingw

dusky coral Apr 2, 2024, 2:06 PM

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And how are you compiling, i.e. with what command?

latent grail Apr 2, 2024, 2:07 PM

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native kestrel ```#ifndef MATCHINGPROBLEM_H_INCLUDED #define MATCHINGPROBLEM_H_INCLUDED #pragm...

why is the header that seems to be matching problem.h define genetic algorithm solver

native kestrel Apr 2, 2024, 2:07 PM

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dusky coral And how are you compiling, i.e. with what command?

oh um is this g++ ?

latent grail Apr 2, 2024, 2:07 PM

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normally you'd expect it to define matching problem

latent grail Apr 2, 2024, 2:07 PM

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dusky coral And how are you compiling, i.e. with what command?

looks a bit like code block

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so that'd be my bet

native kestrel Apr 2, 2024, 2:08 PM

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latent grail looks a bit like code block

YES

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codeblock

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sorry

latent grail Apr 2, 2024, 2:08 PM

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mandatory mention that beginner introductory videos don't have a good average quality

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especially if it's only 1 hour

dusky coral Apr 2, 2024, 2:08 PM

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Also why are you declaring 2 functions inside your main?

native kestrel Apr 2, 2024, 2:10 PM

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dusky coral Also why are you declaring 2 functions inside your main?

should i be making it into only one function?

native kestrel Apr 2, 2024, 2:10 PM

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latent grail especially if it's only 1 hour

i've watched multiple

dusky coral Apr 2, 2024, 2:10 PM

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No, not necessarily, but you just can't declare functions inside other functions

native kestrel Apr 2, 2024, 2:11 PM

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oh? is that why it might be an error

dusky coral Apr 2, 2024, 2:15 PM

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There seem to be multiple errors like e.g. you not defining the class MatchingProblem anywhere but presumably defining GeneticAlgorithmSolver in 2 different header files (we only see the MatchingProblem.h file, but in there you defined GeneticAlgorithmSolver but never MatchingProblem.

Also in your header why are you using 2 include guards?
Either use the ifndef, define, endif chain or just use the pragma once, but there's no need for both in the same file

native kestrel Apr 2, 2024, 2:16 PM

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dusky coral There seem to be multiple errors like e.g. you not defining the class `MatchingP...

i see.. let me implement these and come back, thank you for having a look Bsmile

candid mothBOT Apr 2, 2024, 2:21 PM

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@native kestrel Has your question been resolved? If so, type !solved :)

native kestrel Apr 2, 2024, 9:03 PM

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ERROR MSG:

latent grail Apr 2, 2024, 9:15 PM

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what do you expect this to do/achieve GeneticAlgorithmSolver solver(problem, numParameters, 5000, 100);
and how did you ensure it would work/succeed to do what you wanted

native kestrel Apr 2, 2024, 9:18 PM

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latent grail what do you expect this to do/achieve `GeneticAlgorithmSolver solver(problem, nu...

to set up the parameters of solver, with Nc (candidate parameter sets) = 5000 and Ns (solutions taken to be parents to form next generation) = 100

this would find their costs, and sort list in order of increasing cost i think

latent grail Apr 2, 2024, 9:19 PM

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you didn't answer the second part

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got to leave but GeneticAlgorithmSolver is a type

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you want to create an instance of it

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to do that you need a constructor that matches the argument you're passing in

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you're passing in 4 arguments

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there are no constructor that take 4 arguments

native kestrel Apr 2, 2024, 9:20 PM

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latent grail to do that you need a constructor that matches the argument you're passing in

oh is this to do with the cpp file for it...?

latent grail Apr 2, 2024, 9:20 PM

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might I suggest you take up a tutorial on how to write classes in c++

native kestrel Apr 2, 2024, 9:20 PM

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latent grail might I suggest you take up a tutorial on how to write classes in c++

okay

native kestrel Apr 3, 2024, 3:20 PM

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latent grail might I suggest you take up a tutorial on how to write classes in c++

hi i'm so sorry, but i'm getting this error now? i'm not sure if its my code or my project's settings? 😭

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or something with the void parts of my code

latent grail Apr 3, 2024, 3:23 PM

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where did you define those member functions

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most likely you've put them in their own .cpp files, so the question is how you've told codeblocks that those files were part of your project, and should be compiled and linked together with whatever .cpp file contains your main function

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I think it also has to be said by this point that I really don't recommend using codeblock as your c++ ide, but I also was too lazy to argue the point or try to figure out if you had any constraints that forced you to use it

native kestrel Apr 3, 2024, 3:28 PM

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latent grail I think it also has to be said by this point that I really don't recommend using...

unfortunately i'm required to use codeblocks 😭

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m_catdie

latent grail Apr 3, 2024, 3:29 PM

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haven't looked in details but you have multiple .cpp files, so the pending issue is how yo'uve told codeblocks about all of them

latent grail Apr 3, 2024, 3:29 PM

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native kestrel hi i'm so sorry, but i'm getting this error now? i'm not sure if its my code or...

based just on that it seems likely you have told it about them, because it doesn't seem like you have a codeblock project

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so I'd assume that in some way shape or form codeblocks is only trying to compile one cpp file

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and I don't use codeblock so I can't help you with setting that up

native kestrel Apr 3, 2024, 3:30 PM

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but they are all on the same folder?

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oh

latent grail Apr 3, 2024, 3:30 PM

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cause you seem to be using codeblocks builtin build system

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ok but being in the same folder means little to codeblock

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like codeblock almost certainly shouldn't try to compile CW3.layout

native kestrel Apr 3, 2024, 3:31 PM

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oh

latent grail Apr 3, 2024, 3:31 PM

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so that's generally just not how it works

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the build system has to be told in some way about what files are part of the project and what files it has to deal with

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google "codeblock multiple files compilation" or "codeblock setting up project" or whatever

native kestrel Apr 3, 2024, 3:32 PM

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okay thanks

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do u also suggest i just redo the project again?

candid mothBOT Apr 3, 2024, 3:37 PM

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@native kestrel Has your question been resolved? If so, type !solved :)

latent grail Apr 3, 2024, 3:37 PM

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I don't follow why you would/should

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about any project setup allows you to add existing files

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and if codeblock doesn't with its projects then it's really something that politically correct speech cannot name

candid mothBOT Apr 5, 2024, 3:38 PM

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This question is being automatically marked as stale.
If your question has been answered, type !solved.
If your question is not answered feel free to bump the post or re-ask.
Take a look at !howto ask for tips on improving your question.

native kestrel Apr 6, 2024, 1:17 PM

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!howto ask

candid mothBOT Apr 6, 2024, 1:17 PM

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native kestrel !howto ask

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native kestrel Apr 6, 2024, 1:18 PM

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!solved

candid mothBOT Apr 6, 2024, 1:18 PM

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Thank you and let us know if you have any more questions!

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#new to c++ & not sure how to solve this error?