Hello all,

I will be appreciated if someone tells me a way to calculate a summation

like the following in a shorter way (the number of variables could be

higher like 81, 125, ...).

variable Jx equal v_Jx1+v_Jx2+v_Jx3+v_Jx4+v_Jx5+v_Jx6+v_Jx7&

+v_Jx8+v_Jx9+v_Jx10+v_Jx11+v_Jx12+v_Jx13+v_Jx14&

+v_Jx15+v_Jx16+v_Jx17+v_Jx18+v_Jx19+v_Jx20+v_Jx21&

+v_Jx22+v_Jx23+v_Jx24+v_Jx25+v_Jx26+v_Jx27

I used a loop-next-jump command but I got this error:

ERROR: Variable has circular dependency (../variable.cpp:1823)

variable sum equal 0

variable i loop 27

label start_of_loop_5

Hello all,

I will be appreciated if someone tells me a way to calculate a summation

like the following in a shorter way (the number of variables could be

higher like 81, 125, ...).

variable Jx equal v_Jx1+v_Jx2+v_Jx3+v_Jx4+v_Jx5+v_Jx6+v_Jx7&

+v_Jx8+v_Jx9+v_Jx10+v_Jx11+v_Jx12+v_Jx13+v_Jx14&

+v_Jx15+v_Jx16+v_Jx17+v_Jx18+v_Jx19+v_Jx20+v_Jx21&

+v_Jx22+v_Jx23+v_Jx24+v_Jx25+v_Jx26+v_Jx27

I used a loop-next-jump command but I got this error:

ERROR: Variable has circular dependency (../variable.cpp:1823)

variable sum equal 0

variable i loop 27

label start_of_loop_5

#--------------------------------

variable sum equal v_sum+v_Jx$i

#--------------------------------

next i

jump SELF start_of_loop_5

you can escape the circular dependency by using an immediate expansion in

between to carry the sum value to the next loop. check this out:

cat in.loopme

variable i1 equal 1

variable i2 equal 10

variable i3 equal 100

variable i4 equal 1000

variable sum equal 0.0

variable i loop 4

label loop

variable hold equal ${sum}

variable sum equal v_hold+v_i$i

print "i=i sum={sum}"

next i

jump SELF loop

print "final sum=${sum}"

axel

p.s.: please note, that any input in LAMMPS that requires *that* many

variables is probably doing something that is much simpler and more

efficiently (and more likely correctly) done in post-processing. script

languages like python are much more suitable for such tasks. please also

note, that recent LAMMPS versions, if compiled accordingly, also support

python style variables to embed python scriptlets.