# qua.regressCOP.draw: Draw Quantile Regressions using a Copula by Numerical... In wasquith/copBasic: General Bivariate Copula Theory and Many Utility Functions

## Description

Draw a suite of lines for specified nonexceedance probabilities representing the quantile regression (Nelsen, 2006, pp. 217–218) of either V with respect to U or U with respect to V depending upon an argument setting.

## Usage

 ```1 2``` ```qua.regressCOP.draw(f=seq(0.1, 0.9, by=0.1), fs=0.5, cop=NULL, para=NULL, ploton=TRUE, wrtV=FALSE, col=c(4,2), lwd=c(1,2), lty=1,...) ```

## Arguments

 `f` Nonexceedance probability F to perform quantile regression at and defaults to a 10-percent-interval sequence. This vectorization of `f` for this function differs from that in `qua.regressCOP` and `qua.regressCOP2`; `fs` A special value of nonexceedance probability to draw with second values to arguments `col` and `lwd` and defaults to the median (F = 1/2); `cop` A copula function; `para` Vector of parameters or other data structure, if needed, to pass to the copula; `ploton` A logical to toggle on the plot; `wrtV` If `wrtV=FALSE` call `qua.regressCOP` and perform quantile regression of V with respect to U and if `wrtV=TRUE` call `qua.regressCOP2` and perform regression of U with respect to V; `col` A vector of two values for the color of the line to draw, where the first value is used for the `f` probabilities and the second value is used for the `fs` probability; `lwd` A vector of two values for the line width of the line to draw, where the first value is used for the `f` probabilities and the second value is used for the `fs` probability; `lty` The line type to draw; and `...` Additional arguments to pass.

## Value

No values are returned, this function is used for its side effects.

W.H. Asquith

## References

Nelsen, R.B., 2006, An introduction to copulas: New York, Springer, 269 p.

`qua.regressCOP`, `qua.regressCOP2`
 `1` ```# See example in qua.regressCOP documentation ```