sintegral {Bolstad} | R Documentation |
Takes a vector of x values and a corresponding set of postive f(x)=y values and evaluates the area under the curve:
\int{f(x)dx}
.
sintegral(x, fx, n.pts = 256, ret = FALSE)
x |
a sequence of x values. |
fx |
the value of the function to be integrated at x. |
n.pts |
the number of points to be used in the integration. |
ret |
if true returns the partial sums of the integration. |
## integrate the normal density from -3 to 3 x<-seq(-3,3,length=100) fx<-dnorm(x) estimate<-sintegral(x,fx) true.val<-diff(pnorm(c(-3,3))) cat(paste("Absolute error :",round(abs(estimate-true.val),7),"\n")) cat(paste("Relative percentage error :", 100*round((abs(estimate-true.val)/true.val),6),"%\n"))