clean up sample vs. draw in output and doc

[alashworth]

Issue by bob-carpenter
Monday Mar 14, 2016 at 17:21 GMT
Originally opened as stan-dev/stan#1801

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Summary:

We want to follow Andrew's terminology and not confuse a sample (1 or more draws) with a draw.

Description:

• fix in output [may need to go to interfaces for this]
• fix in argument names (wait for Stan 3)
• fix in manual

Reproducible Steps:

Just run CmdStan.

Current Output:

From CmdStan:

#    num_samples = 1000 (Default)`

From RStan:

Samples were drawn using NUTS(diag_e) at Mon Mar 14 13:19:38 2016.

Expected Output:

CmdStan: num_draws = 1000
RStan: Sample was drawn using NUTS.

Current Version:

v2.9.0

[alashworth]

Comment by maverickg
Monday Mar 14, 2016 at 17:25 GMT

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I still remember we had this discussion about sample. I thought in most cases, we are referring to multiple chains. So I have to use samples there.

[alashworth]

Comment by betanalpha
Monday Mar 14, 2016 at 17:43 GMT

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I would avoid the phrase "draw" altogether as it has the physical connotation of an exact sample. Instead stick with "transition"
or "iteration".

On Mar 14, 2016, at 17:21, Bob Carpenter notifications@github.com wrote:

Summary:

We want to follow Andrew's terminology and not confuse a sample (1 or more draws) with a draw.

Description:

fix in output [may need to go to interfaces for this]
fix in argument names (wait for Stan 3)
fix in manual
Reproducible Steps:

Just run CmdStan.

Current Output:

From CmdStan:

num_samples = 1000 (Default)`

From RStan:

Samples were drawn using NUTS(diag_e) at Mon Mar 14 13:19:38 2016.
Expected Output:

CmdStan: num_draws = 1000
RStan: Sample was drawn using NUTS.

Current Version:

v2.9.0

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Reply to this email directly or view it on GitHub.

[alashworth]

Comment by ariddell
Monday Mar 14, 2016 at 18:18 GMT

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I'd support switching from iter to draws (or num_draws if that's what CmdStan is going to use) as the parameter's name in PyStan/RStan 3. It's currently iter.

[alashworth]

Comment by betanalpha
Tuesday Mar 15, 2016 at 15:22 GMT

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Hmm, actually I might recant slightly as there is a difference between "samples" and "exact samples". This is worth discussing in person (and maybe waiting until after I finish this intro to probability theory and computation draft).

[alashworth]

Comment by bob-carpenter
Tuesday Mar 15, 2016 at 19:45 GMT

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OK, when you and Andrew hash it out, let me know, and we
can update the doc accordingly.