Wrong answer

Intel_C_Intel — Thu, 21 Jun 2001 01:11:44 GMT

In executing this section of code in DVF 6.5A an incorrect answer is calculated for "q.efg(i).pos.e." I set a breakpoint at this line. Before pressing the F11 key to step into this statemnet, the values of the affected variables displayed in the watch window were:

	i =1 
	q,n_of_vectors = 1 
	q.step = 0.500000000 
	q.efg(i).pos.e = 1571.38499309947 
	q.prior_efg(i).pos.e = 1571.38499309947 
	q.prior_efg(i).vel.e = 3.97531397560359 
	a1(i).e = -2.1438381921103193E-003

After pressing the F11 key to step into the statement, the
value of "q.efg(i).pos.e" changes to 0.993761498957395. When running the same program in DVF 5.0A the value of "q.efg(i).pos.e" is calculated as 1572.37865459843. Using a calculator out to the sixth decimal place the answer is 1572.378888.

             do 230 i=1, q.n_of_vectors 
                q.efg(i).pos.e  
     +                 =q.prior_efg(i).pos.e 
     +                 +(q.step/2.0d0)*q.prior_efg(i).vel.e 
     +                 +(q.step*q.step/8.0d0)*a1(i).e 
                q.efg(i).vel.e  
     +                 =q.prior_efg(i).vel.e 
     +                 +(q.step/2.0d0)*a1(i).e          
                q.efg(i).pos.f  
     +                 =q.prior_efg(i).pos.f 
     +                 +(q.step/2.0d0)*q.prior_efg(i).vel.f 
     +                 +(q.step*q.step/8.0d0)*a1(i).f 
                q.efg(i).vel.f 
     +                 =q.prior_efg(i).vel.f 
     +                 +(q.step/2.0d0)*a1(i).f          
                q.efg(i).pos.g 
     +                 =q.prior_efg(i).pos.g 
     +                 +(q.step/2.0d0)*q.prior_efg(i).vel.g 
     +                 +(q.step*q.step/8.0d0)*a1(i).g 
                q.efg(i).vel.g 
     +                 =q.prior_efg(i).vel.g 
     +                 +(q.step/2.0d0)*a1(i).g          
230          continue

These are the compiler options I am using in the debug mode.

/check:bounds /check:power /check:overflow /check:underflow
/compile_only /debug:full /nologo /real_size:64 /traceback
/warn:argument_checking /warn:nofileopt /module:"Debug
/" /object:"Debug/" /pdbfile:"Debug
/DF60.PDB" /alignment

Can anyone help me solve this problem? Is there any other information that I could provide to help someone solve the problem? The only thing I know about compilers is how to spell it.

Re: Wrong answer

Steven_L_Intel1 — Thu, 21 Jun 2001 03:39:21 GMT

I suggest sending a copy of your project as a ZIP archive, including everything necessary to reproduce the problem, to us at vf-support@compaq.com

Steve

topic Wrong answer in Software Archive

Wrong answer

Re: Wrong answer