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Calculate dy/dx vector from vectors y and x

Source: R/amp_melt_curve_functions.R
calculate_dydx.Rd

Used in tidyqpcr to calculate dR/dT for a melt curve of fluorescence signal R vs temperature T.

Usage

calculate_dydx(x, y, method = "spline", ...)

Arguments

x

input variable, numeric vector, assumed to be temperature

y

output variable, numeric vector of same length as x, assumed to be fluorescence signal.

method

to use for smoothing:

"spline" default, uses smoothing spline stats::smooth.spline.

"diff" base::diff for lagged difference

...

other arguments to pass to smoothing method.

Value

estimated first derivative of y with respect to x, numeric vector of same length as y.

See also

Other melt_curve_functions: calculate_drdt_plate()

Examples

# create simple curve
x = 1:5
y = x^2

# calculate gradient of curve
#----- use case 1 : using splines
calculate_dydx(x, y)
#> [1] -2.572999 -3.856780 -5.999883 -8.143689 -9.425360

# optional arguments are passed to smooth.splines function
calculate_dydx(x, y, spar = 0.5)
#> [1] -4.847839 -5.178761 -6.000000 -6.821239 -7.152161

#----- use case 2 : using difference between adjacent points
calculate_dydx(x, y, method = "diff")
#> [1] -3 -5 -7 -9 NA