View source: R/getPeakTrough.R

getPeakTrough | R Documentation |

Given vectors `x`

and `y`

, returns their values at the peak or
trough of the smooth (e.g. cubic spline) curve `y ~ x`

.

```
getPeakTrough(x, y = NULL, peak = TRUE, takeoff = FALSE)
getPeak(x, y = NULL, peak = TRUE, takeoff = FALSE)
getTrough(x, y = NULL, peak = FALSE, takeoff = FALSE)
getTakeoff(x, y = NULL, peak = FALSE, takeoff = TRUE)
```

`x` |
vector. |

`y` |
vector. |

`peak` |
logical determining whether peak or trough is returned. |

`takeoff` |
logical determining whether, if |

Optionally the trough can be specified as takeoff, which is defined for a growth velocity curve as the lowest velocity before the pubertal peak, and if there is no peak then there is by definition no takeoff.

A length-2 vector containing the values of `x`

and `y`

at
the peak or trough. If none are identified NA's are returned.

Tim Cole tim.cole@ucl.ac.uk

```
## create mean height velocity curve
data(heights)
m1 <- sitar(age, height, id, heights, 4)
## plot velocity curve
plot(m1, 'v')
## mark peak, trough and takeoff
xy <- plot_v(m1)
points(t(getPeak(xy)), pch=17)
points(t(getTrough(xy)), pch=25, col=2, bg=2)
points(t(getTakeoff(xy)), pch=25, col=3, bg=3)
```

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.