inst/scripts/like_scale_compare.R

In ashiklom/PEcAnRTM: PEcAn functions used for radiative transfer modeling

pkg_path <- "~/Projects/pecan/pecan/modules/rtm"
devtools::document(pkg_path)
devtools::install(pkg_path)

library(PEcAnRTM)

params <- c('N' = 1.4, 
            'Cab' = 40,
            'Car' = 8,
            'Cw' = 0.01,
            'Cm' = 0.01)
sensor <- "identity"
data(sensor.rsr)
generate_obs <- function(i){
  obs.raw <- prospect(params, 5)[,1] + generate.noise()
  obs <- spectral.response(obs.raw, sensor)
  return(obs)
}

n_obs <- 3
obs <- do.call(cbind, lapply(seq_len(n_obs), generate_obs))

invert.options <- default.settings.prospect
invert.options$model <- function(params) spectral.response(prospect(params,5)[,1], sensor)
invert.options$ngibbs.min <- 5000
invert.options$ngibbs.step <- 2000
invert.options$ngibbs.max <- 100000
invert.options$do.lsq <- TRUE
invert.options$nchains <- 3
invert.options$likelihood_scale <- 6.83/2101

samp_scaled <- invert.auto(obs, invert.options,
                           return.samples = TRUE,
                           parallel = TRUE)

invert.options$likelihood_scale <- 1
samp_unscaled <- invert.auto(obs, invert.options,
                           return.samples = TRUE,
                           parallel = TRUE)

results <- rbind(samp_scaled$results, samp_unscaled$results)
results[, grep("Cw\\.q", colnames(results))]