Special Plots in EMT

Sometimes, you want to give plots in Euler Math Toolbox (EMT) a special look. Let us demonstrate an example. The following is the German tax function (no guarantee!).

>function  map s (x:scalar) ...
$if x<8130 then$    return 0;
$elseif x<13470 then y=(x-8130)/10000;$    return (933.7*y+1400)*y;
$elseif x<52881 then y=(x-13470)/10000;$    return (228.74*y+2397)*y+1014;
$elseif x<250730 then$    return 0.42*x-8196;
$else$    return 0.45*x-15718;
$endif$endfunction
>shrinkwindow(>smaller); ...
>plot2d("s",0,125000,xl="x",yl="s",title="German Income Tax"):

This very basic plot is okay. We already applied the shrinkwindow() command with parameter „smaller=true“ to give the y-label a bit more room. This is necessary if the y-labels are bigger numbers. But we might want to do more.

We want to do the following things. We want

• blue grid lines and text,
• a larger font,
• thicker plot lines,
• added points, where the definition of the tax function changes,
• an aspect ratio so that the plot becomes more landscape,
• more room on the left side, where the text S subscript 2012 should appear.

To do this, we must use more primitive routines of EMT.

>clg; ...
>aspect(1.5); setfont(12pt,15cm); ...
>window(250,50,950,880); ...
>col=rgb(0,0,0.4); ...
>defaulttextcolor=col; defaultgridcolor=col; ...
>framecolor(col); ...
>setplot(0,125000,0,s(125000)); frame();  ...
>xgrid(0:25000:125000); ygrid(0:10000:50000); ...