c - Incompatible pointer type, expected float * but argument is of type float (*)[2]

Question

#define N 5
#define Nv 2

float Cities[N][Nv]={ {0,1}, {3,4}, {1,2}, {5,1} ,{8,9}};
void PrintVec2(float *a, int n) {   
   
    int i;
    for (i = 0; i < (n / 2); i++) printf("
%f %f", a[2 * i], a[2 * i + 1]);
    printf("
");
}

//somewhere I call this
PrintVec2(Cities,N*Nv);

New*Nv is a number, integer. How to fix this warning?

question from:https://stackoverflow.com/questions/65545629/incompatible-pointer-type-expected-float-but-argument-is-of-type-float-2

Answer 1

The prototype:

void PrintVec2(float *a, int n)

Does not match the input parameter:

PrintVec2(Cities,N*Nv);

The function prototype is looking for the address of the array. Change it to send &Cities[0][0]:

PrintVec2(&Cities[0][0],N*Nv);