error when passing a pre-computed distance matrix to the diss_method in mbl()

[l-ramirez-lopez]

the following error is thrown: append(neighborhoods, diss_to_neighbors(diss_xr_xu, k = k, k_diss = k_diss.. object 'neighborhoods' not found

[l-ramirez-lopez]

To reproduce the error:

library(prospectr)
data(NIRsoil)

# Proprocess the data using detrend plus first derivative with Savitzky and
# Golay smoothing filter
sg_det <- savitzkyGolay(
  detrend(NIRsoil$spc,
          wav = as.numeric(colnames(NIRsoil$spc))
  ),
  m = 1,
  p = 1,
  w = 7
)

NIRsoil$spc_pr <- sg_det

# split into training and testing sets
test_x <- NIRsoil$spc_pr[NIRsoil$train == 0 & !is.na(NIRsoil$CEC), ]
test_y <- NIRsoil$CEC[NIRsoil$train == 0 & !is.na(NIRsoil$CEC)]

train_y <- NIRsoil$CEC[NIRsoil$train == 1 & !is.na(NIRsoil$CEC)]
train_x <- NIRsoil$spc_pr[NIRsoil$train == 1 & !is.na(NIRsoil$CEC), ]

# Example 1
# A mbl implemented in Ramirez-Lopez et al. (2013,
# the spectrum-based learner)
# Example 1.1
# An exmaple where Yu is supposed to be unknown, but the Xu
# (spectral variables) are known
my_control <- mbl_control(validation_type = "NNv")

## The neighborhood sizes to test
ks <- seq(40, 140, by = 20)

sbl <- mbl(
  Xr = train_x,
  Yr = train_y,
  Xu = test_x,
  k = ks,
  method = local_fit_gpr(),
  diss_method = f_diss(train_x, test_x),
  diss_usage = "none",
  control = my_control,
  scale = TRUE
)

[l-ramirez-lopez]

fixed