Wisp sigmoid function, implemented in R

This function provides an R implementation of the wisp sigmoid function. It assumes the parameters Rt, tslope, and tpoint have already been warped by wisp_warp.

Usage

wisp_sigmoid(x, Rt, tslope, tpoint)

Arguments

x

Numeric, input spatial position, either a scalar, vector, or 2D array/matrix

Rt

Numeric vector, rate parameters for the wisp function. Degree of the wisp model will be length of this vector minus 1.

tslope

Numeric vector, slope scalars for the wisp function. Must be one less than the length of Rt.

tpoint

Numeric vector, transition points for the wisp function. Must be one less than the length of Rt.

Value

Numeric vector or matrix, wisp sigmoid values for given input. Returned object will have the same dimensions as input x.

Examples

# A single rate block (degree 0) is just a constant
wisp_sigmoid(c(1, 5, 10), Rt = 3, tslope = numeric(0), tpoint = numeric(0))
#> [1] 3 3 3

# Two rate blocks separated by one transition point: far from the transition
# point, the sigmoid recovers each block's asymptotic rate
wisp_sigmoid(c(-1e3, 1e3), Rt = c(1, 9), tslope = 1, tpoint = 0)
#> [1] 1 9