id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
525	Problem with Series Lazy Evaluation	Christian Paz	Víctor de Buen Remiro	"I had an error inmersed into a estimation system that brings an unexpected error the first time compiled, and the second time the error did not happen.

Then, I discovered that when series are not ""forced"" to exist, the same code can result in different values. For example:

//Code to change dating and getting the last not null date of the transformed serie
Serie um_diario = SubSer(Rand(0,1, Diario), y2006m01, y2007m02 );
Serie um=Do(DatCh(um_diario, Semanal, SumS));
Date x=Last(um);

Matrix OOO = SerMat(um);
Serie  dos = MatSerSet(OOO, Dating(um), First(um))[1];

Date y=Last(um);
Text If(x!=y, WriteLn(""Last was ""+FormatDate(x)+"" and now it is ""+FormatDate(y)));

I expected x==y because um did not change in the middle of these two sentences.

Even TOL is Lazy, the moment when I do a ""Last"", the serie should be evaluated. Also see that in um creation a Do sentence is used.

Thanks in advance.
Christian"	defect	closed	highest		TimeSetAlgebra	1.1.6	normal	fixed