derivative: Derivative of fitted polynomial
In quantchem: Quantitative chemical analysis: calibration and evaluation of results

Description Usage Arguments Details Value Author(s) See Also Examples

Calculate derivative of polynomial for given x.

1	derivative(obj, x)

`obj`	an object of class 'lm', fitted in `y ~ x + I(x^2) + I(x^3) + ...` way.
`x`	a vector of x values

This function is called via the other high level functions, but it can be also called directly.

A vector of calculated derivatives.

Lukasz Komsta

lm

x = 1:10
y = jitter(x+x^2)
fit = lm(y~x+I(x^2))
derivative(fit,1:10)

Loading required package: MASS
Loading required package: outliers
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If you use this package, please cite the recent paper containing description of this software:
Komsta, L. Chemometric and statistical evaluation of calibration curves in pharmaceutical analysis 
           - a short review on trends and recommendations. J. AOAC Int. 2012, 95, 3, 669-672.
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 [1]  2.835864  4.877039  6.918215  8.959390 11.000565 13.041740 15.082915
 [8] 17.124090 19.165265 21.206441