Subtraction two trees?

Grasshopper
1

Hi Everyone, I am new to Grasshopper and I am trying to subtract two trees with branches. I post them below:

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Simply the first panel, A, consists of two branches. The second panel, B, consists of 30 branches (all zero values). If we use A - B component, we get the third panel. I realized that the {0;0;0} in third panel gives 15.11 and the others {0;0;1} … {0;15;1} is 12.70. Why does Grasshopper subtracts only once {0;0} in panel A and then subtract 29 times {0;1} in panel A? I hope this is clear. Actually, I don’t understand how operations are done between branches from different trees? Thank you so much

2

Hi,

Branch numbers don’t matter when components have their inputs as item.
So Grasshopper associated the first branch of A to the first branch of B.
Then, the second branch of A to the second branch of B.
And then, there are 28 remaining branches in B but no matching branch in A, so Grasshopper uses the last branch of A.

You need to use Trim Tree on B.

3

Thank you magicteddy! It is now clear what’s happening. However, I don’t want to trim B. I want to subtract in alternating way, I mean:

  1. The first one in B {0;0;0} to subtract {0;0} in A
  2. The second one in B {0;0;1} to subtract {0;1} in A
  3. The third one in B {0;1;0} to subtract {0;0} in A
  4. The fourth one in B {0;1;1} to subtract {0;1} in A
  5. The fifth one in B {0;2;0} to subtract {0;0} in A
  6. The sixth one in B {0;2;1} to subtract {0;1} in A
    etc … Is that possible?
4

You’ll have to repeat the branches of A I’m afraid.

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AMinusB.gh (17.3 KB)

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