mortality.calculation {CTFS}R Documentation

Compute Annual Mortality Rates and Confidence Limits given N, S and Time

Description

A simple function to calculate mortality and confidence limits from N0 (number alive at the outset), S (number of survivors), and time (time interval). Values can be vectors or scalars.

Usage

mortality.calculation(N0, S, meantimeint)

Arguments

N0 number of trees at the first census
S number of trees that survived to the second census, N - D
meantimeint interval between censuses in years for trees in the first census

Details

This function is called many times by mortality. It can be used directly but it is primarily intended as an internal function. N0, S and meantimeint can be single values or vectors. For full details on computation of mortality rate and confidence limits see CTFS.mortality.

Value

mortality.calculation returns a dataframe with the following components:

N0 number of trees at the first census
S number of trees that survived to the second census, N - D
D number of dead trees
rate annual mortality rate
lowerCI lower 95% confidence interval
upperCI upper 95% confidence interval
meantimeint mean number of years between intervals

Author(s)

Rick Condit, Pamela Hall

See Also

CTFS.mortality

Examples

## Not run: 
# 1. Default use of mortality.calculation()

mortality.calculation(500, 490, 5)

# N0   S  D        rate     lowerCI     upperCI meantimeint
# 1 500 490 10 0.004040541 0.002214243 0.007415848           5

# 2. Input values as vectors
N0 = c(100, 100, 100)
S = c(90, 80, 70)
time = c(5, 5, 5)
mortality.calculation(N0,S,time)

# N0  S  D       rate    lowerCI    upperCI meantimeint
# 1 100 90 10 0.02107210 0.01144898 0.03836600           5
# 2 100 80 20 0.04462871 0.02867126 0.06825114           5
# 3 100 70 30 0.07133499 0.04943058 0.10088494           5
## End(Not run)

[Package CTFS version 1.00 Index]