Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: st: mean and SD by categories
From
Federico Belotti <[email protected]>
To
[email protected]
Subject
Re: st: mean and SD by categories
Date
Tue, 16 Jul 2013 17:37:44 +0200
Did you update -estout- from SSC?
ssc install estout, replace
On Jul 16, 2013, at 5:01 PM, Dherani, Mukesh wrote:
> Thank you Nick and Federico. This code runs fine but ends up on one error message:
>
> . estimation result m(all) not found
>
> While I digest the code can you please let me know why?
>
> BW,m
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of Federico Belotti
> Sent: 16 July 2013 14:09
> To: [email protected]
> Subject: Re: st: mean and SD by categories
>
> Ops. Sorry... I wrote the code too quickly
>
> qui {
> local lab
> cap mat drop all mean sd up lo
> forval a=1/2 {
> forval b=1/7 {
> forval c=1/5 {
> sum bmi if sex==`a' & agegp==`b' & ses==`c'
> mat mean = nullmat(mean) \ r(mean)
> mat sd = nullmat(sd) \ r(sd)
> mat up = nullmat(up) \ r(mean)+(1.96*r(sd)/sqrt(r(N)))
> mat lo = nullmat(lo) \ r(mean)-(1.96*r(sd)/sqrt(r(N)))
> local lab `"`lab' "sex=`a' agegp=`b' ses=`c'""'
> }
> }
> }
> mat all = (mean,sd,lo,up)
> mat rown all = `lab'
> mat coln all = mean sd lb ub
> noi estout m(all), varw(22) mlab(,none) }
>
>
>
> On Jul 16, 2013, at 3:02 PM, Nick Cox wrote:
>
>> You need to take square roots of the sample sizes in calculating
>> standard errors.
>> Nick
>> [email protected]
>>
>>
>> On 16 July 2013 13:56, Federico Belotti <[email protected]> wrote:
>>> This could be a strategy to get a table using Ben Jann -estout-
>>> command
>>>
>>> qui {
>>> forval a=1/2 {
>>> forval b=1/7 {
>>> forval c=1/5 {
>>> sum bmi if sex==`a' & agegp==`b' & ses==`c'
>>> mat mean = nullmat(mean) \ r(mean)
>>> mat sd = nullmat(sd) \ r(sd)
>>> mat up = nullmat(up) \ r(mean)+(1.96*r(sd)/r(N))
>>> mat lo = nullmat(lo) \ r(mean)-(1.96*r(sd)/r(N))
>>> local lab `"`lab' "sex=`a' agegp=`b' ses=`c'""'
>>> }
>>> }
>>> }
>>> mat all = (mean,sd,lo,up)
>>> mat rown all = `lab'
>>> mat coln all = mean sd lb ub
>>> noi estout m(all), varw(22) mlab(,none) }
>>>
>>> Federico
>>>
>>> On Jul 16, 2013, at 2:23 PM, Nick Cox wrote:
>>>
>>>> There are various problems with your approach.
>>>>
>>>> 1. The immediate problem is that you cycle over combinations of
>>>> categories creating local macros with names like mean111, sd111, and
>>>> so forth.
>>>>
>>>> But a command like
>>>>
>>>> display mean111
>>>>
>>>> is understood by Stata to mean that you want to see a value of a
>>>> variable -mean111- or a scalar -mean111-, but you have no such
>>>> variable or scalar, hence the message you received.
>>>>
>>>> To see the value of a local macro, you would need to do something
>>>> like
>>>>
>>>> display `mean111'
>>>>
>>>> 2. Adding +/- 1.96 SD to the mean is an attempt to get 95%
>>>> confidence intervals. But there are at least two problems here. 1.96
>>>> is an optimistic multiplier and a more accurate multiplier would be
>>>> based on the t-distribution. However, that's secondary compared with
>>>> using SDs when you should be using standard errors.
>>>>
>>>> 3. A strategic difficulty here is that creating lots of local macros
>>>> first is not a good way to create graphs. In fact if you are a
>>>> novice in programming trying to program graphs from scratch is not advisable.
>>>> In your case 70 cross-combinations seems likely to produce only a
>>>> very complicated graph. Much depends on whether each
>>>> cross-combination is well enough represented to show stable patterns.
>>>>
>>>> -stripplot- from SSC may be of help. It has a -ci- option that means
>>>> that confidence intervals are shown for you.
>>>>
>>>> Nick
>>>> [email protected]
>>>>
>>>>
>>>> On 16 July 2013 12:43, Dherani, Mukesh <[email protected]> wrote:
>>>>> Dear all,
>>>>> I am very novice in programming.
>>>>> I have a dataset with BMI by three categorical variables age (7 groups), sex (2 groups) and SES (5 groups). I was to generate a line graph showing mean BMI with 95%CI by age , sex and SES. Below is my code to create local that I want to use in twoway line graph:
>>>>>
>>>>> forval a=1/2 {
>>>>> forval b=1/7 {
>>>>> forval c=1/5 {
>>>>> sum bmi if sex==`a' & agegp==`b' & ses==`c'
>>>>> local mean`a'`b'`c'=r(mean)
>>>>> local sd`a'`b'`c'=r(sd)
>>>>> local up`a'`b'`c'=r(mean)+(1.96*r(sd)) local
>>>>> lo`a'`b'`c'=r(mean)-(1.96*r(sd)) di mean`a'`b'`c' sd`a'`b'`c'
>>>>> up`a'`b'`c' lo`a'`b'`c'
>>>>> }
>>>>> }
>>>>> }
>>>>>
>>>>>
>>>>> At the end of this command stata says mean111 was not found!
>>>>> Secondly, I want graph to show me mean bmi (y axis) and age (x axis) for each ses for each sex separately. Should I carry this out in the loop or outside the loop?
>>>>>
>>>>> Any help is highly appreciated.
>>>>>
>>>>> BW,m
>>>>>
>>>>>
>>>>> *
>>>>> * For searches and help try:
>>>>> * http://www.stata.com/help.cgi?search
>>>>> * http://www.stata.com/support/faqs/resources/statalist-faq/
>>>>> * http://www.ats.ucla.edu/stat/stata/
>>>>
>>>> *
>>>> * For searches and help try:
>>>> * http://www.stata.com/help.cgi?search
>>>> * http://www.stata.com/support/faqs/resources/statalist-faq/
>>>> * http://www.ats.ucla.edu/stat/stata/
>>>
>>> --
>>> Federico Belotti, PhD
>>> Research Fellow
>>> Centre for Economics and International Studies University of Rome Tor
>>> Vergata
>>> tel/fax: +39 06 7259 5627
>>> e-mail: [email protected]
>>> web: http://www.econometrics.it
>>>
>>>
>>> *
>>> * For searches and help try:
>>> * http://www.stata.com/help.cgi?search
>>> * http://www.stata.com/support/faqs/resources/statalist-faq/
>>> * http://www.ats.ucla.edu/stat/stata/
>>
>> *
>> * For searches and help try:
>> * http://www.stata.com/help.cgi?search
>> * http://www.stata.com/support/faqs/resources/statalist-faq/
>> * http://www.ats.ucla.edu/stat/stata/
>
> --
> Federico Belotti, PhD
> Research Fellow
> Centre for Economics and International Studies University of Rome Tor Vergata
> tel/fax: +39 06 7259 5627
> e-mail: [email protected]
> web: http://www.econometrics.it
>
>
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/faqs/resources/statalist-faq/
> * http://www.ats.ucla.edu/stat/stata/
>
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/faqs/resources/statalist-faq/
> * http://www.ats.ucla.edu/stat/stata/
--
Federico Belotti, PhD
Research Fellow
Centre for Economics and International Studies
University of Rome Tor Vergata
tel/fax: +39 06 7259 5627
e-mail: [email protected]
web: http://www.econometrics.it
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/faqs/resources/statalist-faq/
* http://www.ats.ucla.edu/stat/stata/