# vwstrip.normal: Varying width strip for a normal or log-normal distribution In denstrip: Density Strips and Other Methods for Compactly Illustrating Distributions

## Description

Draws a varying width strip for a normal or log-normal distribution with the given mean and standard deviation, based on computing the density at a large set of equally-spaced quantiles.

## Usage

 ```1 2``` ```vwstrip.normal(mean, sd, log=FALSE, nx=1000, ...) panel.vwstrip.normal(...) ```

## Arguments

 `mean` Mean of the normal distribution. `sd` Standard deviation of the normal distribution. `log` If `TRUE` then the strip for a log-normal distribution, with mean and SD on the log scale `mean` and `sd`, respectively, is plotted. This may be useful for illustrating hazard ratios or odds ratios. `nx` Number of points to evaluate the density at. `...` Further arguments passed to `vwstrip`, for example, `at` to position the strip on the y-axis, or `lattice=TRUE` to use as a lattice panel function. `panel.vwstrip.normal(x,...)` is equivalent to `vwstrip.normal(x, lattice=TRUE,...)`.

## Author(s)

Christopher Jackson <[email protected]>

`vwstrip`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21``` ```x <- seq(-4, 4, length=10000) dens <- dnorm(x) plot(x, xlim=c(-5, 5), ylim=c(-1, 2), xlab="x", ylab="", type="n", axes=FALSE) axis(1) vwstrip(x, dens, at=0, width=0.4, limits=qnorm(c(0.005, 0.995))) vwstrip.normal(0, 1, at=1, width=0.4, limits=qnorm(c(0.005, 0.995))) ### log-normal distribution sdlog <- 0.5 x <- rlnorm(10000, 0, sdlog) plot(x, xlim=c(0, 5), ylim=c(-1, 3), xlab="x", ylab="", type="n", axes=FALSE) axis(1) abline(v=1, lty=2, col="lightgray") vwstrip(x, at=0, width=0.4, ticks=exp(-sdlog^2), limits=qlnorm(c(0.005,0.975),0,sdlog)) # tick at theoretical maximum density vwstrip(x, at=1, width=0.4, bw=0.1, ticks=exp(-sdlog^2), limits=qlnorm(c(0.005,0.975),0,sdlog)) vwstrip.normal(0, sdlog, log=TRUE, at=2.5, width=0.4, nx=1000, ticks=exp(-sdlog^2), limits=qlnorm(c(0.005,0.975),0,sdlog)) ```