compare two lists

[jayasree]

i got two lists which has the insertion point and the end point

ex ins_pt (-3.5432 4.5678)
end_pt (-3.5432 4.5678)

When i use (equal ins_pt end_pt) it returns nil.

Is there any other way to compare both lists and return T.

Thanks,
Jayasree

[Adesu]

Hi jayasree,test it

(setq ex_ins_pt '(-3.5432 4.5678))
(setq end_pt '(-3.5432 4.5678))
(if
  (equal ex_ins_pt end_pt 0.0001)
  (princ "\nThat right,it's same value")
  (princ "\nThat wrong,it's not same value")
  )

i got two lists which has the insertion point and the end point

ex ins_pt (-3.5432 4.5678)
end_pt (-3.5432 4.5678)

When i use (equal ins_pt end_pt) it returns nil.

Is there any other way to compare both lists and return T.

Thanks,
Jayasree

[CarlB]

If your points are calculated, you may think they're equal but they may differ in the 16th decimal point. You may want to use a fuzz factor, as in (equal PtA PtB 0.0000001)

[mguzik@nospamlawson-fishe]

If my memory is correct equal is used for comparing list and eq for
variables.

So using the two points above in the following will yield true:

(setq ins_pt '(-3.5432 4.5678)
end_pt '(-3.5432 4.5678))
(if (equal ins_pt end_pt)
(princ "\nThey are equal ")
(princ "\nThey are not equal")
)
(princ)

Also try with two lists that are not exactly the same with the optional
fuzz input variable of equal:

(setq ins_pt '(-3.5432 4.567)
end_pt '(-3.5432 4.566))
(if (equal ins_pt end_pt 0.005)
(princ "\nThey are equal ")
(princ "\nThey are not equal")
)

Hope this helps comparing lists