mechanical: mechanical model: use an exponential function to describe the...

In mengluchu/APMtools: statistical air pollution mapping tools

Description

mechanical model: use an exponential function to describe the coefficients away from roads

Usage

mechanical(
  variabledf,
  y_var = c("day_value", "night_value", "value_mean"),
  pop_var = "pop3k",
  distance_centre,
  roadtypes = 3,
  buffers_in,
  buffers_out,
  training,
  test,
  nls2start = NA,
  Road_varname = "ROAD",
  normalize = F
)

Arguments

variabledf	the dataframe containing predictors and dependent variable
y_var	name of the dependent variable.
pop_var	the name of an additional variable as a linear term, usually population withn a buffer, a string.
distance_centre	the distance to centre from each buffer. (b2-b1)/2 + b1
training	the index for the rows used for training.
test	the index for the rows used for testing.
nls2start	the start value for nls2. if providing an nls2start, the nls2 from nls2 package is used. Details see nls2.
Road_varname	the name of variables contains road buffers, e.g. 'ROAD'
normalize	if True, the road ring is normalised by the area (default is false)

Details

This method used nls for modelling. This function also prints errormatrix, the exponential model; plot coefficient. The modelling and evaluation should be separated at a later stage, now putting together for exploration only.

Value

An object of nls

Examples

mechanical(inde_var,'day_value',pop_var = 'pop5k', distance_centre = distance_centre, training, test)

mengluchu/APMtools documentation built on Jan. 27, 2022, 2:41 a.m.