Forward marching vectors

Hi All, I am trying to plot admissible thrust lines in masonry arches using GH. Starting at the left I know the start position and the vector, the line length is defined by where it intersects the relevant radial line on the arch. The start position for the next line is the intersection point for the previous line. I have created a definition that does this, but the definition is written the same way you would do it by hand. It is a very cumbersome definition. Can anyone think of a more elegant way to do this? and hopefully a method where the number of segments could be adjusted? (39.3 KB)


It would ne better for everyone if you internalized the data coming from Excel so we don’t all need the plugin and Excel file.

And yes, definitely(!), there are much beter ways to do this:


Hi Joseph, thanks for the reply. Ahh whoops, I thought I had internalised the data but I did it on the non-standard component (not very helpful!).

Please see the (41.5 KB)
attached definition, hopefully now with data internalised.

Tricky! This took awhile to understand. Since each point depends on the previous point, I resorted to an Anemone loop (white group). (26.0 KB)

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Hi Josheph,
Thanks for the reply, that is a big improvement on what I had done. I havn’t used loops before but I will have a play around with them. Thanks for the help.


Anemone is a wonderful tool. I used the “Classic” Loop Start and Loop End components that let you see progress during the loop, which I find satisfying to watch and helpful to debug. There is also a pair of “Fast” components that do basically the same thing but way faster, without showing anything. (26.7 KB)