% --- start of displayed preamble in the book ---

% --- start of displayed preamble in the book ---
input graph
% --- end of displayed preamble in the book ---
% graphic converted to gray in book using 'color2gray'
defaultfont:="ptmr8r";
warningcheck:=0;
beginfig(1)
draw begingraph(2.5in,1.75in);
gfill "yearw.dat" withcolor red;
autogrid(grid.bot,itick.rt)
withcolor .5white;
frame.llft;
endgraph;
endfig;
end;