create default window win graphwin("tic-tac-toe"set coordinates to go from ( , in the lower left to ( , in the upper right win setcoords( draw vertical lines line(point( , )point( , )draw(winline(point( , )point( , )draw(windraw horizontal lines line(point( , )point( , )draw(winline(point( , )point( , )draw(winanother benefit of this approach is that the size of the window can be changed by simply changing the dimensions used when the window is created ( win graphwin("tic-tac-toe" )because the same coordinates span the window (due to setcoordsthe objects will scale appropriately to the new window size using "rawwindow coordinates would require changes in the definitions of the lines we can apply this idea to simplify our graphing future value program basicallywe want our graphics window to go from through (representing yearsin the dimension and from to , (representing dollarsin the dimension we could create just such window like this win graphwin("investment growth chart" win setcoords( then creating bar for any values of year and principal would be simple each bar starts at the given year and baseline of and grows to the next year and height equal to principal bar rectangle(point(year )point(year+ principal)there is small problem with this scheme can you see what have forgottenthe eleven bars will fill the entire windowwe haven' left any room for labels or margins around the edges this is easily fixed by expanding the coordinates of the window slightly since our bars start at we can locate the left side labels at - we can add bit of white space around the graph by expanding the coordinates slightly beyond that required for our graph little experimentation leads to this window definitionwin graphwin("investment growth chart" win setcoords(- ,- here is the program againusing the alternative coordinate systemfutval_graph py