Graphical comparison between reference, validation and estimation data (to analyze tracker
results only).
This routine displays a graphical comparison between reference & validation samples $\left\{y_k\in\mathbb{R}, k\in [1, N]\right\}$ & $\left\{y_k\in\mathbb{R}, k\in [1, N_v]\right\}$ obtained for different values $\left\{x_k\in\mathbb{R}^n,k \in [1, N]\right\}$ & $\left\{x_k\in\mathbb{R}^n,k \in [1, N_v]\right\}$ of some explanatory variables $x$, and an associated approximating function $f:\mathbb{R}^n\rightarrow\mathbb{R}$. The local approximation error $f(x_k)y_k$ and the rootmeansquare error are also computed to evaluate the accuracy of the approximation (see errapprox
for a complete description).
plosurfs(pop,best,X,Y,names,Xv,Yv,{options})
The first seven input arguments are mandatory:
pop 
Structure containing the main information about the individuals of the final population (as provided by tracker )

best 
Index of the best individual in the final population, w.r.t. fitness (as provided by tracker ) 
X 
Values $\left\{x_k\in\mathbb{R}^n,k \in [1, N]\right\}$ of the explanatory variables $x$ used for optimization ($n\times N$ array, where X(:,k) corresponds to $x_k$). Note that $n$ can only be equal to 2 in this routine. 
Y 
Samples $\left\{y_k\in\mathbb{R}, k\in [1, N]\right\}$ used for optimization ($1\times N$ array where Y(k) corresponds to $y_k$). 
names 
Names of the explanatory variables $x$ ($1\times n$ cell array of strings). 
Xv 
Values $\left\{x_k\in\mathbb{R}^n,k \in [1, N_v]\right\}$ of the explanatory variables $x$ used for validation ($n\times N_v$ array, where X(:,k) corresponds to $x_k$). Note that $n$ can only be equal to 2 in this routine. 
Yv 
Samples $\left\{y_k\in\mathbb{R}, k\in [1, N_v]\right\}$ used for validation ($1\times N_v$ array where Y(k) corresponds to $y_k$). 
The eigth input argument Options
is an optional structured variable with fields:
axlim 
Row vector [1x6] containing a set of userdefined axis limits corresponding to the Matlab axis comand 
viewpoint 
This option is applicable only if 3D graphs are to be displayed ($n=2$). The row vector [1x2] represents the deviation with respect to the default viewpoint [145 30]

lsapprox
olsapprox
qpapprox
tracker
koala
errapprox
plotapprox
plosurfaces
plofronts