3.5 1D samples

This section is devoted to visualization of 1D data arrays. 1D means the data which depend on single index (parameter) like curve in parametric form {x(i),y(i),z(i)}, i=1...n. Most of samples will use the same data for plotting. So, I put its initialization in separate function

void mgls_prepare1d(mglData *y, mglData *y1=0, mglData *y2=0, mglData *x1=0, mglData *x2=0)
{
  register long i,n=50;
  if(y) y->Create(n,3);
  if(x1)  x1->Create(n);    if(x2)  x2->Create(n);
  if(y1)  y1->Create(n);    if(y2)  y2->Create(n);
  mreal xx;
  for(i=0;i<n;i++)
  {
    xx = i/(n-1.);
    if(y)
    {
      y->a[i] = 0.7*sin(2*M_PI*xx) + 0.5*cos(3*M_PI*xx) + 0.2*sin(M_PI*xx);
      y->a[i+n] = sin(2*M_PI*xx);
      y->a[i+2*n] = cos(2*M_PI*xx);
    }
    if(y1)  y1->a[i] = 0.5+0.3*cos(2*M_PI*xx);
    if(y2)  y2->a[i] = 0.3*sin(2*M_PI*xx);
    if(x1)  x1->a[i] = xx*2-1;
    if(x2)  x2->a[i] = 0.05+0.03*cos(2*M_PI*xx);
  }
}

or using C functions

void mgls_prepare1d(HMDT y, HMDT y1=0, HMDT y2=0, HMDT x1=0, HMDT x2=0)
{
  register long i,n=50;
  if(y)   mgl_data_create(y,n,3,1);
  if(x1)  mgl_data_create(x1,n,1,1);
  if(x2)  mgl_data_create(x2,n,1,1);
  if(y1)  mgl_data_create(y1,n,1,1);
  if(y2)  mgl_data_create(y2,n,1,1);
  mreal xx;
  for(i=0;i<n;i++)
  {
    xx = i/(n-1.);
    if(y)
    {
      mgl_data_set_value(y, 0.7*sin(2*M_PI*xx) + 0.5*cos(3*M_PI*xx) + 0.2*sin(M_PI*xx), i,0,0);
      mgl_data_set_value(y, sin(2*M_PI*xx), i,1,0);
      mgl_data_set_value(y, cos(2*M_PI*xx), i,2,0);
    }
    if(y1)  mgl_data_set_value(y1, 0.5+0.3*cos(2*M_PI*xx), i,0,0);
    if(y2)  mgl_data_set_value(y2, 0.3*sin(2*M_PI*xx), i,0,0);
    if(x1)  mgl_data_set_value(x1, xx*2-1, i,0,0);
    if(x2)  mgl_data_set_value(x2, 0.05+0.03*cos(2*M_PI*xx), i,0,0);
  }
}