Ecco il grafico con solo la fascia arancione:
Regola bene i coefficienti che moltiplicano le espressioni delle curve, devono essere gli stessi per tutti grafici.
Adesso credo che tu sappia fare tutti i grafici che ti servono della sequenza.
Saluti.
`\documentclass[11pt,a4paper]{report}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage{layaureo}
\usepackage{pgfplots}
\pgfplotsset{compat=1.3}
\pgfplotsset{compat=newest}
\pgfkeys{/pgf/number format/.cd,fixed,precision=2}
\pgfplotsset{grid style={gray!35}}
\pgfplotsset{
mysmall/.style={
/pgfplots/grid=major,
/pgfplots/xminorgrids=true,
/pgfplots/xtick align=outside,
/pgfplots/ytick align=outside,
every axis y label/.style=
{at={(ticklabel cs:0.5)},anchor=near ticklabel},
legend style={font=\tiny},
/pgfplots/legend cell align=left,
/pgfplots/tick label style={font=\scriptsize}
}
}
\begin{document}
\begin{tikzpicture}%
\begin{semilogyaxis}[mysmall,
width=.6\textwidth,
height=.8\textwidth,
xlabel={$x$},
ylabel={$y$},
xmin=0.1,
xmax=0.4,
ymin=1E-6,
ymax=1,
domain=0.1:0.4,
no markers,
clip=false
]
\addplot[fill,color=orange] {1} \closedcycle;
\addplot[fill,color=white]
{(12.659*x^3-8.3636*x^2+2.1229*x+0.0108)*1.06}
\closedcycle;
% main red curve
\addplot[line width=1pt,color=red]
{12.659*x^3-8.3636*x^2+2.1229*x+0.0108};
% main blue curve
\addplot[line width=1pt,color=blue]
{0.1564*x^2+0.035*x-0.0003};
% rebuilding of the box line
\draw (axis description cs:0,0) rectangle
(axis description cs:1,1);
% rebuilding of the grid line
\newcommand{\vl}[1]{%
\draw[help lines,thin,black!25]
(axis cs:#1,1E-6)–(axis cs:#1,1)}
\vl{0.15};
\vl{0.20};
\vl{0.25};
\vl{0.30};
\vl{0.35};
\node at (axis cs:.25,0.4) {\footnotesize Primo modello};
\node at (axis cs:.25,0.055) {\footnotesize Secondo modello};
\node at (axis cs:.25,2E-4) {\footnotesize terzo modello};
\end{semilogyaxis}
\end{tikzpicture}
\end{document}`