# function polyfitxyerr

Return an n-th order polynomial fit to the vectors X and Y, where y = f(x). The typical error of the dependent variables is given in ERROR. If a variable is given as the 4th argument, it will be overwritten with the chi squared of the fit.
**Syntax**

*result* = polyfitxyerr(X, Y, N, ERROR [, CHISQ])
**Arguments**

X: | A vector. |

Y: | A vector. |

N: | An integer number. |

ERROR: | The error of the Y-values. If this is a real number, all Y-values are assumed to have the same error. If ERROR is a vector, it must have the same length as X and Y and gives the error or each individual Y value. |

CHISQ: | If set to a named variable, the variable is overwritten with the chi-squared of the fit. |

**See also**

function polyfit

function polyfitxy

function polyfit2d

function polyfit2derr