[Yuji]

I am making a code which generates simple mesh with C++.
I can generate the simple mesh with ASCII but cannot do it with Binary.
Can you teach me how to get Binary data?
I attach a figure of mesh data of ASCII with paraview and code.
Best,
Yuji



#include <cmath>
#include <fstream>
#include <iostream>
#include <vector>
#include <cstring>

using namespace std;

int main() {
int jmax, kmax, lmax, idomein; // nufile_binaryer of grid points in xi, eta and zeta direction
double xl, yl, zl; // horizontal, vertical, depth computational dommain
double dnx, dny, dnz, dx, dy, dz; // 1/dnx = dx (grid spacing)
double unit = 1.0;
int index;
int ibinary = 0;

// boundary nufile_binaryer
int bcfluid = 0, bcnonslip = 1, bcmovingwall = 2, bcinflow = 3, bcoutflow = 4, bcdammy = -1;

// parameters set
// jmax = 201;
// kmax = 101;
// lmax = 1;
xl = 3.0;
yl = 1.0;
zl = 0.0;
dnx = 50.0;
dny = 100.0;
dnz = 1.0;
dx = unit / dnx;
dy = unit / dny;
dz = unit / dnz;
printf("Grid Space: dx = %lf, dy = %lf, dz = %lf", dx, dy, dz);
jmax = dnx * xl + 1;
kmax = dny * yl + 1;
lmax = dnz * zl + 1;

idomein = jmax * kmax * lmax;
vector<double> x(idomein, 0.0);
vector<double> y(idomein, 0.0);
vector<double> z(idomein, 0.0);
vector<int> bc(idomein, 10);
printf("Nufile_binaryer of Grid Poits: jmax = %d, kmax = %d, lmax = %d, total = %d", jmax, kmax, lmax, idomein);

for (int l = 0, index = 0; l <= lmax - 1; l++) {
for (int k = 0; k <= kmax - 1; k++) {
for (int j = 0; j <= jmax - 1; j++, index++) {
x[index] = dx * double(j);
y[index] = dy * double(k);
z[index] = dz * double(l);
// boundary condition and fluid region
if ((l == 0 && j == 0) || (l == 0 && j == jmax - 1) || (l == 0 && k == 0) || (l == 0 && k == kmax - 1)) {
bc[index] = bcdammy;
} else if (l == 0 && j == 1) {
bc[index] = bcinflow;
} else if ((l == 0 && j == jmax - 2) || (l == 0 && k == kmax - 2)) {
bc[index] = bcoutflow;
} else if (l == 0 && k == 1) {
bc[index] = bcnonslip;
} else {
bc[index] = bcfluid;
}
}
}
}

// if (ibinary == 0) {
ofstream file("grid.dat");
if (!file.is_open()) {
cerr << "failed to open grid.dat" << endl;
return -1;
}
// ascii
file << "TITLE = " mesh data "" << endl;
file << "VARIABLES = "X", "Y", "Z", "BC" " << endl;
file << "ZONE T = "GRID", I=" << jmax << ", J=" << kmax << ", K=" << lmax << ", F=POINT" << endl;
// for (int index = 0; index <= idomein; index++) {
for (int l = 0, index = 0; l <= lmax - 1; l++) {
for (int k = 0; k <= kmax - 1; k++) {
for (int j = 0; j <= jmax - 1; j++, index++) {
file << x[index] << " " << y[index] << " " << z[index] << " " << bc[index] << endl;
}
}
}
file.close();
//}
//} else {
// binary
ofstream file_binary("grid_binary.dat", ios::out | ios::binary);
if (!file_binary.is_open()) {
cerr << "failed to open grid.plt" << endl;
return -1;
}
file_binary << "TITLE = "mesh data"" << endl;
file_binary << "VARIABLES = "X", "Y", "Z", "BC" " << endl;
file_binary << "ZONE T = "GRID", I=" << jmax << ", J=" << kmax << ", K=" << lmax << ", F=POINT" << endl;
// file.write((const char*)&jmax, sizeof(int));
// file.write((const char*)&kmax, sizeof(int));
// file.write((const char*)&lmax, sizeof(int));
file_binary.write((const char*)x.data(), idomein * sizeof(double));
file_binary.write((const char*)y.data(), idomein * sizeof(double));
file_binary.write((const char*)z.data(), idomein * sizeof(double));
file_binary.write((const char*)bc.data(), idomein * sizeof(int));

file_binary.close();
// }
}