这幅图是plot(as.numeric(ts(afew_sca$`United States`)), type="l")

为了求面积我试了用：
f = approxfun(x = 1:434, y = as.numeric(ts(afew_sca$`United States`)))
integrate(f,lower = 1+1e-05,upper = 434-1e-05,subdivisions = 1000)
但是报错
Error in integrate(f, lower = 1 + 1e-05, upper = 434 - 1e-05, subdivisions = 1000) : roundoff error was detected


去掉subdivisions = 1000：
f = approxfun(x = 1:434, y = as.numeric(ts(afew_sca$`United States`)))
integrate(f,lower = 1+1e-05,upper = 434-1e-05)

又有报错
Error in integrate(f, lower = 1 + 1e-05, upper = 434 - 1e-05) : maximum number of subdivisions reached


求大神指点！