Optimize multiple variable sets

Correct me if I'm wrong, but isn't the minimal x value in your example the 
same regardless of what positive coefficient you apply to x? If that is 
the case, you would expect the same min(x) for each iteration.

i.e. in the interval [0,1] the minimum x value of x^2 + x is the same as 
x^2 + 100000000*x, at x = 0.

You're wrong --- slightly. The returned $minimum is the x, the y is  $objective. But the interval given doesn't bracket the minimum, as you'll clearly see if you put int=c(-10,10). The only puzzling bit is that optimize() doesn't actually return the left endpoint, but rather the first evaluation point inside the interval. The rather wide tolerance of .Machine$double.eps^0.25  == 0.0001220703 probably plays a role in this.

Peter Dalgaard
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com