pith_measure: Calibrate ring-width series

Description Usage Arguments Details Value Author(s) References Examples

View source: R/pith_measure.R

Description

This function can calibrate the ring-width series using arcs of inner rings.

Usage

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pith_measure(ring.data, inner.arc = TRUE, last.yr = NULL,
  color = "black", border.type = 16, label.cex = 1.5)

Arguments

ring.data

A magick image object produced by ring_read.

inner.arc

A logical value indicating whether to calibrate the ring-width series using the arcs of inner rings. See details below.

last.yr

NULL or an integer giving the year of formation of the left-most ring. If NULL, border numbers (starting from 1) are used instead of years.

color

Color for labels.

border.type

Symbol for ring borders. See pch in points for possible values and shapes.

label.cex

The magnification to be used for years or border numbers.

Details

This function allows the user to create a path, and manually mark ring borders by clicking on the graphical window.

An example demonstrated with pictures can be found in the package vignette. Type vignette('pith-MtreeRing') to see this example.

Value

A data frame of the calibrated ring-width series. The measurements units are millimeters (mm)

Author(s)

Jingning Shi

References

Duncan R. (1989) An evaluation of errors in tree age estimates based on increment cores in Kahikatea (Dacrycarpus dacrydiodes). New Zealand Natural Sciences 16(4), 1-37.

Examples

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img.path <- system.file("missing_pith.png", package = "MtreeRing")

## Read the image:
t1 <- ring_read(img = img.path, dpi = 1200, plot = FALSE)

## Use the arcs of inner rings to calibrate ring-width series:
t2 <- pith_measure(t1, inner.arc = TRUE, last.yr = 2016)

## Try another method to measure ring widths:
t3 <- pith_measure(t1, inner.arc = FALSE, last.yr = 2016)

JingningShi/MtreeRing documentation built on Dec. 10, 2019, 9:37 a.m.