Message Boards

8616 Views

8 Replies

3 Total Likes

View groups...

Follow this post

Share this post:

GROUPS:

Mathematica Graphics and Visualization Wolfram Language Statistics and Probability

repeated sampling from a list

Posted 10 years ago

POSTED BY: Philip Cooper

8 Replies

Sort By:

Posted 10 years ago

Even more efficient would be to use: f[n_] := Mean /@ RandomChoice[data, {n , 7}]

POSTED BY: Sander Huisman

Posted 10 years ago

Thank you!

POSTED BY: Philip Cooper

Posted 10 years ago

Right you are! I think the coffee hadn't kicked in yet. But the code is right ;-) (I an often code in Mathematica before I can speak sensibly....)

POSTED BY: David Reiss

Posted 10 years ago

Slightly more efficient, I suspect: f[n_]:=Mean /@ Partition[RandomChoice[data, 7 n], 7] Also note (!) the distinction that this needs to be `RandomChoice` rather than `RandomSample`. `RandomChoice` allows random selection from the list of `data` without using any of the `data` more than once. `RandomSample` allows for choosing a random datum more than once. I assume that this is actually what you want. If you actually want `RandomSample` then the original approach posted above by Melvyn would be better, but the lenght of `data` must be greater than or equal to 7.

POSTED BY: David Reiss

Posted 10 years ago

Wow! Thank you! Cool code! I think you accidentally wrote it backwards? RandomChoice - samples "with replacement", meaning you can draw the same list item more than once in a sample, whereas RandomSample will not (let you). But for (my) statistical purposes, either is fine as the sample is less than 5% of the population (the data set,) and the data set is greater than 30 items.

POSTED BY: Philip Cooper

Posted 10 years ago

I am extremely grateful, thank you! I changed ListPlot to Histogram. That's what I wanted. And your code looks pretty darn optimum to me! Thanks x 1e6! Attachments: