topIndices {CGNM}

topIndices

Description

CGNM find multiple sets of minimizers of the nonlinear least squares (nls) problem by solving nls from various initial iterates. Although CGNM is shown to be robust compared to other conventional multi-start algorithms, not all initial iterates minimizes successfully. One can visually inspect rank v.s. SSR plot and manually choose number of best fit acceptable parameters. By using this function "topIndices", we can obtain the indices of the "numTopIndices" best fit parameter combinations.

Usage

topIndices(CGNM_result, numTopIndices)

Arguments

CGNM_result

(required input) A list stores the computational result from Cluster_Gauss_Newton_method() function in CGNM package.

numTopIndices

(required input) An integer .

Value

A vector of natural number that contains the indices of accepted approximate minimizers found by CGNM.

Examples

model_analytic_function=function(x){

 observation_time=c(0.1,0.2,0.4,0.6,1,2,3,6,12)
 Dose=1000
 F=1

 ka=x[1]
 V1=x[2]
 CL_2=x[3]
 t=observation_time

 Cp=ka*F*Dose/(V1*(ka-CL_2/V1))*(exp(-CL_2/V1*t)-exp(-ka*t))

 log10(Cp)
}

observation=log10(c(4.91, 8.65, 12.4, 18.7, 24.3, 24.5, 18.4, 4.66, 0.238))

CGNM_result=Cluster_Gauss_Newton_method(
nonlinearFunction=model_analytic_function,
targetVector = observation,
initial_lowerRange = c(0.1,0.1,0.1), initial_upperRange =  c(10,10,10),
num_iter = 10, num_minimizersToFind = 100, saveLog = FALSE)

topInd=topIndices(CGNM_result, 10)

## This gives top 10 approximate minimizers
CGNM_result$X[topInd,]