Given a vector (or a matrix) representing a curve (or set of
curves, columnwise),
the area (or set of areas) is calculated using the trapezoidal rule.
Arguments
- x
vector of samples for the dependent variable.
- y
vector or matrix of samples for the independent variable.
In the case of the latter, curves are organized column-wise.
Value
area (areas) under the sampled curve (curves).
Examples
x <- seq(0, 1, by = 0.0001)
y <- exp(x)
# Compare with true area of exp( 1 ) - 1 = 1.718282...
areaEstimate <- trapz(x, y)