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Aug 22, 2013 3:29 PM
(5978 views)

Hello All,

I am attempting to randomly select 20% of the observations in my table below 200, and then exclude those observations from any analysis. In other words, do a random row selection both at a given percentage and below a certain threshold. Thanks for any pointers!

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Two options I can think of.

1. Use Select Where to select rows with values < 200. Make a subset using selected rows and choose Link to Original Table. Make subset of that using a random sample and also choose Link to Original Table. Now select all the rows in the final subset and they will also be selected in the original, because of the linking.

2. Make a new column with a formula such as :value < 200 & random uniform() < 0.2.

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Re: Random row selection below a certain threshold

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Two options I can think of.

1. Use Select Where to select rows with values < 200. Make a subset using selected rows and choose Link to Original Table. Make subset of that using a random sample and also choose Link to Original Table. Now select all the rows in the final subset and they will also be selected in the original, because of the linking.

2. Make a new column with a formula such as :value < 200 & random uniform() < 0.2.

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Re: Random row selection below a certain threshold

Thanks Xan,

that works great!