Add CRW

Julia/src/model-move.jl

@@ -0,0 +1,33 @@
+struct StateXYD <: Patter.State
+    map_value::Float64
+    x::Float64
+    y::Float64
+    angle::Float64  
+end
+
+struct ModelMoveXYD{T, U, V, W} <: ModelMove
+    map::T
+    mobility::U
+    dbn_length::V
+    dbn_angle_delta::W
+end 
+
+function Patter.simulate_step(state::StateXYD, model_move::ModelMoveXYD, t::Int64)
+    length = rand(model_move.dbn_length)
+    angle  = state.angle + rand(model_move.dbn_angle_delta)
+    x      = state.x + length * cos(angle)
+    y      = state.y + length * sin(angle)
+    map_value = Patter.extract(model_move.map, x, y)
+    StateXYD(map_value, x, y, angle)
+end 
+
+function Patter.logpdf_step(state_from::StateXYD, state_to::StateXYD, model_move::ModelMoveXYD, t::Int64, length::Float64, angle::Float64) 
+    angle_delta = abs_angle_difference(angle, state_from.angle)
+    logpdf(model_move.dbn_length, length) + logpdf(model_move.dbn_angle_delta, angle_delta)
+end 
+
+function Patter.states_init(state_type::Type{StateXYD}, coords)
+    N = nrow(coords)
+    coords.angle = rand(N) .* 2 .* π
+    return coords
+end 

src/model-move.R

@@ -0,0 +1,6 @@
+move_xyd <- function(mobility = "750.0",
+                     dbn_length = "truncated(Gamma(1.0, 750.0), upper = 750.0)",
+                     dbn_angle_delta = "Normal(0, 0.5)") {
+  patter:::julia_check_exists("env")
+  glue('ModelMoveXYD(env, {mobility}, {dbn_length}, {dbn_angle_delta});')
+}