WARDEN (version 2.0.1)

adj_val: Adjusted Value Calculation

Description

This function calculates an adjusted value over a time interval with optional discounting. This is useful for instances when adding cycles may not be desirable, so one can perform "cycle-like" calculations without needing cycles, offering performance speeds. See the vignette on avoiding cycles for an example in a model.

Usage

adj_val(
  curtime,
  nexttime,
  by,
  expression,
  discount = NULL,
  vectorized_f = FALSE
)

Value

Numeric. The calculated adjusted value.

Arguments

curtime

Numeric. The current time point.

nexttime

Numeric. The next time point. Must be greater than or equal to curtime.

by

Numeric. The step size for evaluation within the interval.

expression

An expression evaluated at each step. Use .time as the variable within the expression.

discount

Numeric or NULL. The discount rate to apply, or NULL for no discounting.

vectorized_f

boolean, FALSE by default. If TRUE, evaluates the expression once using .time as a vector. If FALSE, it repeatedly evaluates the expression with time as a single value (slower).

Details

The user can use the .time variable to select the corresponding time of the sequence being evaluated. For example, in curtime = 0, nexttime = 4, by = 1, .time would correspond to 0, 1, 2, 3. If using nexttime = 4.2, 0, 1, 2, 3, 4

Examples

# Define a function or vector to evaluate
bs_age <- 1
vec <- 1:8/10

# Calculate adjusted value without discounting
adj_val(0, 4, by = 1, expression = vec[floor(.time + bs_age)])
adj_val(0, 4, by = 1, expression = .time * 1.1)
#same result since .time * 1.1 can be vectorized w.r.t time
adj_val(0, 4, by = 1, expression = .time * 1.1, vectorized_f = TRUE)

# Calculate adjusted value with discounting
adj_val(0, 4, by = 1, expression = vec[floor(.time + bs_age)], discount = 0.03)