Gravity analysis step

[civil]

Hi
I use this code for gravity analysis:
set GravSteps 20
system UmfPack;
constraints Transformation;
test NormDispIncr 1.0e-6 100 0
algorithm Newton
numberer RCM;
analysis Static
analyze $GravSteps
loadConst -time 0.0;

why the result are different when GravSteps change?
For example the result for “recorder Node -file data/reaction.out -time -node 1 2 3 -dof 1 reaction” are (only gravity load are applied):
GravSteps=1
1 -1.0408e-010 -1.87174e-010 -5.3495e-011
GravSteps=5
0.2 -3.61114e-012 -7.982e-012 -6.92437e-012
0.4 1.90281e-011 1.45865e-011 6.63114e-012
0.6 -9.48723e-012 -1.07071e-010 -9.72113e-011
0.8 -3.70303e-012 -2.67928e-011 -5.62615e-011
1 -2.01017e-011 1.56981e-010 -2.28702e-012

Why the result are different in t=1?

[fmk]

the e-10 and through e-12 ARE VERY SMALL NUMBERS .. do you have any load applied, is this a free node you are recording?