How does uniformal scaling of polyline looks like (without transformation)?

If I have a set of points of polyline

Do I do something like this?

//Get center of polyline

```
for (int i = 0; i < n; i++)
curveCenter += points[i];
curveCenter /= n;
for (int i = 0; i < n; i++) {
Vector3D vector = curveCenter-points[i];
vector.Unitize();
points[i] += vector*(1-ratio)*0.5;
}
```