Numerical integration · CMNA Laboratory
Gauss-Legendre quadrature does not chop the interval into equal pieces. It chooses special nodes and weights so surprisingly few evaluations can integrate polynomials very accurately.
CMNA's Gaussian integration driver multiplies each function value by a corresponding weight and sums the result. This lab maps standard Gauss-Legendre nodes from [-1,1] onto your interval so you can see exactly where R samples the function.
Bring your own integrand
Write f(x) in R, choose an interval and a 5-, 10-, or 20-point rule, then inspect every weighted evaluation.
Preparing R…f(x)| node | x | f(x) | weight | contribution |
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