The initial value of r (r =0.235) resulted in LV = 1.015.
Try other values close to the initial value of r.
r = 0.2378 gives exactly LV = 1.
(exactly = 1)
(close to 1)
Equation of Lotka : must = 1
By using
ITERATION to find r
This r is obtained on an assumption that the generation is developing in a descrete way. However, it can be used as an initial value for iteration to
get a more accurate value of r by using Lotka's equation.
From these data, r (the intantaneous/continuous
rate of increase) is approximated:
Tc is the Average Generation Time (sometimes symbol G is used)
by Rudy C Tarumingkeng
SUMMARY
px = probability of an individual to live into the next age-class, is used in Leslie transition matrix, to predict the dynamics of the population.
Proportion of
mortality, qx
Number of
Mortality, dx
Proportion of ax,
lx
AGE CLASS,
x
Survivorship
(mx)
Eggs laid,
yx
OBSERVED
DATA, ax
Since no remaining individuals in age-class 10,
except in several cases for facilitation of the
computation, data in x10 is included in the table.
A Mathcad program - primer for Lifetable analysis
Correction to the text: Dinamika Populasi by
Rudy C Tarumingkeng
pp. 59-63 (In Indonesian), 1994.

This program was originally prepared by the author in 1993 using earlier version of MathcadR (Ver. 4?), but it should work with any version of Mathcad R.

Five hundred mosquito larvae were collected and reared in laboratory. The cohort were observed every two days for any surviving individuals. The age-class (x ) is two days. ax denotes the s urviving individuals in each class. The surviving individuals are depicted in vector a below.

At x=10 the original individuals were all dead (a 10 =0). During the rearing period the number of surviving eggs were laid: at x=6, 1600; at x=7, 360; at x=8, 300; and at x=9, 25.

The data are hypothetic. It was assumed that all individuals in the cohort and their offspring were females. The idea is to show how to compute the essential statistics in lifetable analysis.