May users of procedures such as Gnuplot and Gnupltxy find themselves wanting more control over the graphics such as provided by Excel among other packages. One can use the Gdxxrw procedure to gain access to such graphics. In particular, one can set up a graph in Excel then use Gdxxrw to place new data in the spreadsheet in the area graphed and whenever the spreadsheet is subsequently opened the new and improved graph will be ready. Let me illustrate this using a new sheet called mygraph in our gdxxrwss.xls. Here I prepare a graph that uses the data in b2-d7 for the lines and the labels in a11 and a12 to describe those lines. I would have also liked to use the labels in a13-a15 to name the graph and label it's axes but could not figure a strategy to do this with Excel commands or a simple macro.
In turn I go into a GAMS program in this case graphss.gms and put in GDX file creation and Gdxxrw commands
set allels /X X values
Newline1 Data for line 1
NewLine2 Data for line 2
Title A graph of 2 GAMS generated lines
XAXIS Whatever the X axis label
YAXIS Whatever the X axis label /
points /i1*i6/;
table mydata(points,allels) data to graph
x NewLine1 NewLine2
i1 1 1
i2 4 3
i3 7 4
i4 8 5
i5 12 8
i6 14 9 ;
mydata(points,"Newline2")=mydata(points,"x")+mydata(points,"Newline1");
execute_unload 'tograph.gdx' allels, mydata;
execute 'gdxxrw tograph.gdx trace=3 o=gdxxrwss.xls par=mydata Rng=mygraph!a1:d7';
execute 'gdxxrw tograph.gdx trace=3 o=gdxxrwss.xls set=allels Rng=mygraph!a10 rdim=1';
where the Gdxxrw commands save the data to be graphed into the cells a1:d7 and a set using SET where I placed potential titles as explanatory text in cells a10 and below. In turn when I open the spreadsheet and the mygraph sheet as reproduced below where I find the data, legend and lines graphed have been derived from GAMS.
