Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: creating cross tables/ matrices with expected/ observed frequencies from long data set |

Date |
Sat, 22 Sep 2012 10:58:58 +0100 |

Sorry, but I am not clear how the second question differs from the first. One table you are asking for has 300 columns (one for each ID). Really? When I have that many columns, I give up on conventional tables and just go for -list-s. -groups- (SSC) shows my strategy in action, although I am not promising that it is an answer to any problem of yours. On Sat, Sep 22, 2012 at 9:48 AM, Nick Darson <nick.darson@googlemail.com> wrote: > Well, if there is not other solution, I guess I will have to reshape > the data. I just wanted to double check whether there is a "tab"-like > command that can create cross-tabs of different groups from the same > variable.... > > What about the second question (for the expected frequencies)? Is > there any table function (in the sense of "list") that simply shows > the values of a group from a variable instead of describing its > summary/ modes/ etc? > > BTW: Thanks for the reply, Nick! > > > > On Sat, Sep 22, 2012 at 5:16 PM, Nick Cox <njcoxstata@gmail.com> wrote: >> I think that this question is self-cancelling, as I guess that you >> need to restructure your data to get tables that you want, but seem to >> rule that out as an acceptable solution. >> >> Nick >> >> On Sat, Sep 22, 2012 at 1:35 AM, Nick Darson <nick.darson@googlemail.com> wrote: >> >>> I would like to create several tables/matrices with expected >>> frequencies and observations (to be able to carry out a Chi Square >>> test of how well my model describes the data). >>> I have the following data set (each person chose from 2 sets, the >>> first one containing 3 option, the second one containing 4 options), >>> with ID=individuals (300), set=choice set, option= option, choice= >>> chosen option (dummy), Prob= expected probability for each individual >>> based on my random-effects logit model. >>> >>> ID Set Option Choice Prob >>> 1 1 A 0 0.2 >>> 1 1 B 1 0.7 >>> 1 1 C 0 0.1 >>> 1 2 D 0 0.1 >>> 1 2 E 0 0.2 >>> 1 2 F 1 0.4 >>> 1 2 G 0 0.3 >>> 2…. >>> >>> First I would need a cross-table with observed frequencies for the two >>> choice sets (looking as follows): >>> A B C >>> D >>> E >>> F >>> G >>> >>> I am familiar with the tab-command, but a bit lost how do to obtain >>> the table given my data-set arrangement? Any help would be >>> appreciated. >>> >>> >>> Then I would need the same table as above, but with expected (joint) >>> probabilities instead of observed frequency. For this, I had the >>> following strategy in mind: >>> 1.) Create 2 matrices, one for each choice set >>> 2.) Transpose one matrix and multiply to obtain joint probability >>> >>> For 1.), I would need one table with the probabilities listed (column= >>> Individuals; rows= options) as follows: >>> >>> ID1 ID2 ID3 ….. >>> A 0.2 ….. >>> B 0.7 >>> C 0.1 >>> (and same table/ matrix for set 2). >>> How would I do this in Stata? To my understanding, Tabs and tabstats >>> only provide summaries etc, but I want the original value of prob >>> listed? >>> Any help would be appreciated! >>> BTW: this is a simplification of the original data set (more sets and >>> options) and I would like to do several things in one set…therefore, I >>> “keep”/”reshape” combos would not be suitable. * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: creating cross tables/ matrices with expected/ observed frequencies from long data set***From:*Nick Darson <nick.darson@googlemail.com>

**References**:**st: creating cross tables/ matrices with expected/ observed frequencies from long data set***From:*Nick Darson <nick.darson@googlemail.com>

**Re: st: creating cross tables/ matrices with expected/ observed frequencies from long data set***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: creating cross tables/ matrices with expected/ observed frequencies from long data set***From:*Nick Darson <nick.darson@googlemail.com>

- Prev by Date:
**Re: st: Quantile regression** - Next by Date:
**st: spmap** - Previous by thread:
**Re: st: creating cross tables/ matrices with expected/ observed frequencies from long data set** - Next by thread:
**Re: st: creating cross tables/ matrices with expected/ observed frequencies from long data set** - Index(es):