---

11.38 Sample ‘dat_extra’ ¶

Example of envelop, sew, smooth and resize.

MGL code:

subplot 2 2 0 '':title 'Envelop sample':new d1 1000 'exp(-8*x^2)*sin(10*pi*x)'
axis:plot d1 'b':envelop d1 'x':plot d1 'r'
subplot 2 2 1 '':title 'Smooth sample':ranges 0 1 0 1
new y0 30 '0.4*sin(pi*x) + 0.3*cos(1.5*pi*x) - 0.4*sin(2*pi*x)+0.5*rnd'
copy y1 y0:smooth y1 'x3':plot y1 'r';legend '"3" style'
copy y2 y0:smooth y2 'x5':plot y2 'g';legend '"5" style'
copy y3 y0:smooth y3 'x':plot y3 'b';legend 'default'
plot y0 '{m7}:s';legend 'none'
legend:box
subplot 2 2 2:title 'Sew sample':rotate 50 60:light on:alpha on
new d2 100 100 'mod((y^2-(1-x)^2)/2,0.1)'
box:surf d2 'b':sew d2 'xy' 0.1:surf d2 'r'
subplot 2 2 3:title 'Resize sample (interpolation)'
new x0 10 'rnd':new v0 10 'rnd'
resize x1 x0 100:resize v1 v0 100
plot x0 v0 'b+ ':plot x1 v1 'r-':label x0 v0 '%n'

C++ code:

void smgl_dat_extra(mglGraph *gr)	// differentiate
{
	gr->SubPlot(2,2,0,"");	gr->Title("Envelop sample");
	mglData d1(1000);	gr->Fill(d1,"exp(-8*x^2)*sin(10*pi*x)");
	gr->Axis();			gr->Plot(d1, "b");
	d1.Envelop('x');	gr->Plot(d1, "r");

	gr->SubPlot(2,2,1,"");	gr->Title("Smooth sample");
	mglData y0(30),y1,y2,y3;
	gr->SetRanges(0,1,0,1);
	gr->Fill(y0, "0.4*sin(pi*x) + 0.3*cos(1.5*pi*x) - 0.4*sin(2*pi*x)+0.5*rnd");

	y1=y0;	y1.Smooth("x3");
	y2=y0;	y2.Smooth("x5");
	y3=y0;	y3.Smooth("x");

	gr->Plot(y0,"{m7}:s", "legend 'none'");	//gr->AddLegend("none","k");
	gr->Plot(y1,"r", "legend ''3' style'");
	gr->Plot(y2,"g", "legend ''5' style'");
	gr->Plot(y3,"b", "legend 'default'");
	gr->Legend();		gr->Box();

	gr->SubPlot(2,2,2);		gr->Title("Sew sample");
	mglData d2(100, 100);	gr->Fill(d2, "mod((y^2-(1-x)^2)/2,0.1)");
	gr->Rotate(50, 60);	gr->Light(true);	gr->Alpha(true);
	gr->Box();			gr->Surf(d2, "b");
	d2.Sew("xy", 0.1);	gr->Surf(d2, "r");

	gr->SubPlot(2,2,3);		gr->Title("Resize sample (interpolation)");
	mglData x0(10), v0(10), x1, v1;
	gr->Fill(x0,"rnd");		gr->Fill(v0,"rnd");
	x1 = x0.Resize(100);	v1 = v0.Resize(100);
	gr->Plot(x0,v0,"b+ ");	gr->Plot(x1,v1,"r-");
	gr->Label(x0,v0,"%n");
}