# Methods by Which a Curve Is Calculated

Unlike point curves, there are a number of Methods, which can be chosen from the Method option menu, for calculating the final curve that results.

Method | Data points or vertices of element define |
---|---|

Control Points | Vertices of the control polygon. |

Through Points | Points on the curve. |

Least Squares by Tolerance and Least Squares by Number | A set of points that the curve approximates or is "fit" to. |

Catmull-Rom | A set of points that is closely approximated. |

These illustrations show the different types of B-spline curves constructed from the same line string.