# Tool to approximate smooth functions by B-splines.

### Description

**bsp** is used to approximate smooth functions by B-splines.

### Usage

1 | ```
bsp(x,kn)
``` |

### Arguments

`x` |
values of the explanatory variable. |

`kn` |
(optional) the number of internal knots . The default value is |

.

### Details

This function uses the routine `bs()`

of the R package *splines*.

### Value

`x` |
the B-spline basis matrix, which is cubic. |

### Author(s)

Luz Marina Rondon <lumarp@gmail.com> and Heleno Bolfarine

### References

De Boor, C. (1978). A practical Guide to Splines. Applied Mathematical Sciences. Springer-Verlag, New York.