ClearAll;
$DefaultFont = {"Times-Roman",10};
Needs["Graphics`Graphics`"];
njags = 100;
mean[c_]:= Gamma[1+1/c];
mu2 = mean[2];mu5 = mean[5];
l2 = Graphics[{Dashing[{0.001,0.01}],Line[{{mu2,0},{mu2,f2[mu2]}}]}];
l5 = Graphics[{Dashing[{0.001,0.01}],Line[{{mu5,0},{mu5,f5[mu5]}}]}];
poly[a_,b_,f_]:= Join[Table[{a+i(b-a)/njags,f[a+i(b-a)/njags]},
				  {i,0,njags}],{{b,0},{a,0}}];
shade[a_,b_,c_,f_]:= Graphics[{GrayLevel[c],Polygon[poly[a,b,f]]}];
f[m_,z_]:= m z^(m-1) E^(-(z)^m);
f2[z_]:= f[2,z];f5[z_]:= f[5,z];
M2 = (Log[2])^(1/2);M5 = (Log[2])^(1/5);
T2[z_]:= (z - mu2)f2[z];

ushading = Show[l2,Axes->True,
				PlotRange->{{0,2.75},{0,0.9}},
				Ticks->{{0.5,{mu2,FontForm[m,{"Symbol",9}]},1.5},{0,0.25,0.5,0.75}},
				PlotLabel->"Probability density",
				AspectRatio->0.92/GoldenRatio,
				AxesLabel->{"x/s","s f"}];
lshading = Show[shade[0,mu2,0.65,T2],shade[mu2,2.75,0.65,T2],
				Graphics[Text[FontForm["+",{"Times-Roman",24}],{1.35,0.1}]],
				Graphics[Text[FontForm["-",{"Times-Roman",30}],{0.4,-0.15}]],
				Axes->True,
				PlotRange->{{0,2.75},{-0.35,0.25}},
				Ticks->{{1.0,1.5,2.0,2.5},
					{-0.2,0,0.2}},
				PlotLabel->"Turning density",
				AxesLabel->{"x/s","T"}];

plotu:= Plot[f2[z],{z,0.001,3}];
plotl:= Plot[T2[z],{z,0.001,3}];
	
upper = Show[ushading,plotu];
lower = Show[lshading,plotl];
Show[GraphicsArray[{{upper},{lower}}],
		PlotLabel->"                    Figure 26.2\n
		Mean of Weibull distribution (c = 2)"]