Figure 4

Landscape of the objective function for the implied volatility. The true values are \(\kappa ^{*}=1.0\) and \(\nu _{0}^{*}=0.2\) in the left plot, and \(\kappa ^{*}=1.0\) and \(\bar{\nu }^{*}=0.2\) in the right plot. There are 35 market samples. The objective function is MSE. The contour plot is rendered by a log-transformation