problem with random output

Hello,

I am trying to use a random component to generate a list of random numbers within a certain range. Its working fine but only when I manually type in how many random numbers I want into the "N" input. But when I plug in a list length from a component earlier in the script (which defines how many random numbers I need) the random component still outputs the correct amount of random numbers but they are all the same number. Im sure im overlooking something simple, please help!

Replies to This Discussion

Permalink Reply by David Rutten on October 15, 2013 at 5:47pm

Hi Joe,

there are no real random numbers in GH. What you get is pseudo-random numbers. A series of pseudo-random numbers is always the same for the same seed value. If you want to generate different sequences, you'll have to provide a different seed for each sequence.

A seed value is just an integer (any integer). You can generate these seeds using a [Series] component, or maybe another Random component. Do note that the random generator in Grasshopper is not a particularly good one. If you pick similar seeds, the resulting random sequences will have a high degree of relatedness. You can sort of get around this by generating very different seeds.

David Rutten

david@mcneel.com

Seattle, WA

Permalink Reply by Andrew Heumann on October 15, 2013 at 7:33pm

Also make sure that the input to your list length component is flattened - otherwise you will get the same sequence (or number) over and over again as you're describing.

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