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rintegralderivative

Retrieve integral expression of a function

Base R provides a function D() that outputs the expression of the derivative of a given function.

For example:

f <- expression(x^3+2*x)
D(f, "x") # with respect to x
# 3 * x^2 + 2

Is there a similar function that would yield the expression of the integral of a function?

I know that stats::integrate() will evaluate the integral of a function for a given interval, but as far as I know, it will not output the expression of the Integral.

Solution

  • As mentioned in the comments, the package Ryacas can do indefinite integrals:

    library(Ryacas)
x = Sym('x')
f = expression(x^3 + 2*x)
Integrate(f, x)
## expression(x^4/4 + x^2)

    There is no base function for integration but for differentiation because differentiation is mechanics, integration is art.