ramp: Create ramp function

In sdbuildR: Easily Build, Simulate, and Visualise Stock-and-Flow Models

Create ramp function

Description

Create a ramp function that increases linearly from 0 to a specified height at a specified start time, and stays at this height after the specified end time.

Usage

ramp(times, start, finish, height = 1)

Arguments

times	Vector of simulation times
start	Start time of ramp
finish	End time of ramp
height	End height of ramp, defaults to 1

Details

Equivalent of Ramp() in Insight Maker

Value

Ramp interpolation function

See Also

step(), pulse(), seasonal()

Examples

# Create a simple model with a ramp function
sfm <- xmile() |>
  build("a", "stock") |>
  # Specify the global variable "times" as simulation times
  build("input", "constant", eqn = "ramp(times, 20, 30, 3)") |>
  build("inflow", "flow", eqn = "input(t)", to = "a")



sim <- simulate(sfm, only_stocks = FALSE)
plot(sim)

# To create a decreasing ramp, set the height to a negative value
sfm <- build(sfm, "input", eqn = "ramp(times, 20, 30, -3)")

sim <- simulate(sfm, only_stocks = FALSE)
plot(sim)

sdbuildR documentation built on Nov. 19, 2025, 5:07 p.m.