cannot convert from "initializer list" - c++

Question

I am new and have an issue in C++. I am creating 3D coordinates, (x, y and z for each corner of a face, then 6 faces) and receive many errors. Here is my code:
#include <vector>
int main()
{
std::vector<int> xyzCoords = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
int x1 = 0;
int y1 = 1;
int z1 = 2;
int x2 = 3;
int y2 = 4;
int z2 = 5;
xyzCoords = {
{ x1, y1, z1, x2, y1, z1, x2, y1, z2, x1, y1, z2 },
{ x1, y2, z1, x2, y2, z1, x2, y2, z2, x1, y2, z2 },
{ x1, y2, z1, x1, y1, z1, x1, y1, z2, x1, y2, z2 },
{ x2, y2, z1, x2, y1, z1, x2, y1, z2, x2, y2, z2 },
{ x1, y2, z2, x1, y1, z2, x2, y1, z2, x2, y2, z2 },
{ x1, y2, z1, x1, y1, z1, x2, y1, z1, x2, y2, z1 }
};
return 0;
}
This the code where the problem occurs. You can see I'm defining xyzCoords as a vector. I'm not sure if this is the correct way to do it. I also don't want to be defining xyz123 separately. What is the best way to achieve this? Shall I use a list, array or vector? Please write the code for how to do this. Thanks!
Errors:
E0289: no instance of constructor "std::vector<_Ty, _Alloc>::vector [with _Ty=int, _Alloc=std::allocator]" matches the argument list
E0349: no operator "=" matches these operands
C2440: 'initializing': cannot convert from 'initializer list' to 'std::vector>'
C2679: binary '=': no operator found which takes a right-hand operand of type 'initializer list' (or there is no acceptable conversion)

Answer 1

Your initialization is unmatch with the type you had declared. You declare a 1D array whereas your initialization is 2D array.
std::vector<int> xyzCoords = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
It should be :
std::vector<std::vector<int>> xyzCoords = {
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
};
You mentioned about xyz coordinate, so why don't you make a class specially used for coordinate, for instance :
struct Point {
int x, y, z;
};
Anyway, I don't recommend you to use naive approach for this problem because it will be a matrix-operation-intensive computation. You should use BLAS/LAPACK library or it's wrapper like Eigen or Armadillo. They are surely far faster.

Answer 2

Perhaps you should restructure your code to something like this, for visibility and better understanding:
#include <vector>
int main()
{
struct Corner
{
int x;
int y;
int z;
Corner(int x, int y, int z) :
x(x), y(y), z(z) {}
};
struct Face
{
Corner c1;
Corner c2;
Corner c3;
Corner c4;
Face(Corner c1, Corner c2, Corner c3, Corner c4) :
c1(c1), c2(c2), c3(c3), c4(c4) {}
};
Corner c1(0, 1, 2);
Corner c2(3, 4, 5);
Face f1(c1, c2, c1, c2);
std::vector<Face> faces = { f1, f1, f1, f1, f1, f1 };
return 0;
}
This creates array of 6 faces with coordinates of the corners (x1,y1,z1) (x2,y2,z2) (x1,y1,z1) (x2,y2,z2)

Answer 3

#include <vector>
struct Vertex {
float x_; // can change these to int
float y_;
float z_;
Vertex() : x_(0), y_(0), z_(0) {}
Vertex( float x, float y, float z ) : x_(x), y_(y), z_(z) {}
explicit Vertex( float val ) : x_(val), y_(val), z_(val) {}
};
struct Face {
Vertex v0_;
Vertex v1_;
Vertex v2_;
Vertex v3_;
Face() :
v0_(Vertex()),
v1_(Vertex()),
v2_(Vertex()),
v3_(Vertex()) {
}
Face( Vertex v0, Vertex v1, Vertex v2, Vertex v3 ) :
v0_(v0),
v1_(v1),
v2_(v2),
v3_(v3) {
}
};
int main() {
std::vector<Face> faces;
// Not exact values the OP is looking for,
// just a quick way to populate the vector of faces
// for demonstration purposes of the usefulness of structs & classes.
for ( unsigned n = 1; n <= 6; n++ ) {
faces.push_back( Face( Vertex(n), Vertex(n+1), Vertex(n+2), Vertex(n+3) ) );
}
return 0;
}