rate_of_change {adc}

Approximate the Instantaneous Rate of Change

Description

Estimate the rate of change or first derivative of the raw mean daily streamflow or the smoothed cubic spline fit between time and mean daily streamflow.

Usage

rate_of_change(discharge, dates, smooth = TRUE)

Arguments

discharge

numeric vector of mean daily discharges

dates

vector of dates corresponding to daily discharge measurements. Must be class "Date".

smooth

logical indicating if the first derivative is calculated using a cubic smoothing spline function. Defaults is TRUE.

Value

Numeric vector with the estimated streamflow rate of change.

Examples

## calculate the first deriv of the smoothed function between Date and streamflow
rate <- rate_of_change(lavaca$Flow, lavaca$Date)
head(rate)

## Return the first deriv on raw measurements
rate2 <- rate_of_change(lavaca$Flow, lavaca$Date, smooth = FALSE)
head(rate2)