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11.110 Sample ‘region’ ¶

Function region fill the area between 2 curves. It support gradient filling if 2 colors per curve is specified. Also it can fill only the region y1<y<y2 if style ‘i’ is used.

MGL code:

call 'prepare1d'
copy y1 y(:,1):copy y2 y(:,2)
subplot 2 2 0 '':title 'Region plot (default)':box:region y1 y2:plot y1 'k2':plot y2 'k2'
subplot 2 2 1 '':title '2 colors':box:region y1 y2 'yr':plot y1 'k2':plot y2 'k2'
subplot 2 2 2 '':title '"i" style':box:region y1 y2 'ir':plot y1 'k2':plot y2 'k2'
subplot 2 2 3 '^_':title '3d variant':rotate 40 60:box
new x1 100 'sin(pi*x)':new y1 100 'cos(pi*x)':new z 100 'x'
new x2 100 'sin(pi*x+pi/3)':new y2 100 'cos(pi*x+pi/3)'
plot x1 y1 z 'r2':plot x2 y2 z 'b2'
region x1 y1 z x2 y2 z 'cmy!'

C++ code:

void smgl_region(mglGraph *gr)
{
	mglData y;	mgls_prepare1d(&y);
	mglData y1 = y.SubData(-1,1), y2 = y.SubData(-1,2);	gr->SetOrigin(0,0,0);
	if(big!=3)	{	gr->SubPlot(2,2,0,"");	gr->Title("Region plot (default)");	}
	gr->Box();	gr->Region(y1,y2);	gr->Plot(y1,"k2");	gr->Plot(y2,"k2");
	if(big==3)	return;
	gr->SubPlot(2,2,1,"");	gr->Title("2 colors");	gr->Box();	gr->Region(y1,y2,"yr");	gr->Plot(y1,"k2");	gr->Plot(y2,"k2");
	gr->SubPlot(2,2,2,"");	gr->Title("'i' style");	gr->Box();	gr->Region(y1,y2,"ir");	gr->Plot(y1,"k2");	gr->Plot(y2,"k2");
	gr->SubPlot(2,2,3,"^_");	gr->Title("3d variant");	gr->Rotate(40,60);	gr->Box();
	gr->Fill(y1,"cos(pi*x)");	gr->Fill(y2,"cos(pi*x+pi/3)");
	mglData x1(y1.nx), x2(y1.nx), z(y1.nx);
	gr->Fill(x1,"sin(pi*x)");	gr->Fill(x2,"sin(pi*x+pi/3)");	gr->Fill(z,"x");
	gr->Plot(x1,y1,z,"r2");		gr->Plot(x2,y2,z,"b2");
	gr->Region(x1,y1,z,x2,y2,z,"cmy!");
}