Thanks, Neil and Nick! Your answers are really helpful!
Best,
Jian Zhang
On Sun, 26 Feb
2006, Nick Cox wrote:
> I can't speak for STATA. The program I know
> is called Stata. Please read the Statalist
> FAQ before posting to be familiar with the
> advice given.
>
> Specific answers below.
>
> Nick
> [email protected]
>
> Jian Zhang
>
> > Dear STATA users,
> >
> > I have a question about making a table using STATA. I
> > couldn't figure out
> > how to make it. Hope that you could help me.
> >
> > The table that I need has the following format:
> >
> > group1 group2 group3
> > variabel 1
> > variabel 2
> > variabel 3
> >
> > The celles are filled with variable means for each group and for each
> > varialbe. For example, the first cell (row 1 and column 1) is
> > the mean of variable 1 for group 1.
> >
> > I know that I can use command table to make the following table:
> >
> > table group, by(mean variable1 mean variable2 mean variable3)
> >
> > variable1 variable2 variable3
> > group1
> > group2
> > group3
> >
> >
> > Since I have so many variables and groups, it would take too
> > much time to
> > convert the format of the secon table to that of the first table
> > manually. I wonder if there is a shortcut way in which I
> > could directly
> > generate the first table?
>
> I can't find anything to do precisely this. Here's a quick
> and dirty program to do it. It's not especially smart about
> row or column labels. Watch for wrapped lines in copying.
>
> *! NJC 1.0.0 26 Feb 2006
> program meantable
> version 8.2
> syntax varlist(numeric) [if] [in] [, by(varname) format(str) stat(str) ]
>
> quietly {
> marksample touse
> if "`by'" != "" markout `touse' `by', strok
> count if `touse'
> if r(N) == 0 error 2000
>
> if "`by'" != "" {
> levels `by' if `touse', clean local(levels)
> local levels : subinstr local levels "." " ", all
> }
> else {
> tempvar by
> gen byte `by' = 1
> local levels "all"
> }
>
> local nstat : word count `stat'
> if `nstat' >= 2 {
> di as err "single statistics only in stat()"
> exit 198
> }
>
> tempvar group
> egen `group' = group(`by') if `touse'
> su `group', meanonly
> local c = r(max)
> numlist "1/`c'"
> local safelevels "`r(numlist)'"
> local r : word count `varlist'
> tokenize `varlist'
> tempname tmatrix
> mat `tmatrix' = J(`r', `c', .)
>
> if "`stat'" == "" local stat "mean"
> if inlist("`stat'", "N", "sum_w", "sum", "mean", "min", "max") {
> local opt "meanonly"
> }
> else if inlist("`stat'", "skewness", "kurtosis") {
> local opt "detail"
> }
> else if inlist("`stat'", "p1", "p5", "p10", "p25", "p50", "p75", "p90", "p95", "p99") {
> local opt "detail"
> }
>
> forval j = 1/`c' {
> forval i = 1/`r' {
> su ``i'' if `group' == `j', `opt'
> matrix `tmatrix'[`i', `j'] = r(`stat')
> }
> }
>
> matrix rownames `tmatrix' = `varlist'
> capture matrix colnames `tmatrix' = `levels'
> if _rc matrix colnames `tmatrix' = `safelevels'
> if "`format'" == "" local format "%4.3f"
> }
>
> mat li `tmatrix', format(`format') noheader
> end
>
> . sysuse auto, clear
> (1978 Automobile Data)
>
> . meantable mpg
>
> all
> mpg 21.297
>
> . meantable mpg, by(rep78)
>
> 1 2 3 4 5
> mpg 21.000 19.125 19.433 21.667 27.364
>
> . meantable mpg turn trunk , by(rep78)
>
> 1 2 3 4 5
> mpg 21.000 19.125 19.433 21.667 27.364
> turn 41.000 43.375 41.067 38.500 35.636
> trunk 8.500 14.625 15.267 13.500 11.455
>
> . meantable mpg turn trunk , by(rep78) format(%2.1f)
>
> 1 2 3 4 5
> mpg 21.0 19.1 19.4 21.7 27.4
> turn 41.0 43.4 41.1 38.5 35.6
> trunk 8.5 14.6 15.3 13.5 11.5
>
> . meantable mpg turn trunk , by(rep78) format(%4.3f) stat(skewness)
>
> . meantable mpg turn trunk , by(rep78) format(%4.1f) stat(p50)
>
> 1 2 3 4 5
> mpg 21.0 18.0 19.0 22.5 30.0
> turn 41.0 43.5 42.0 37.0 36.0
> trunk 8.5 16.0 16.0 13.5 11.0
>
> > A related question is that: is there an option in command table or in
> > other commands that we could automatically indicate the statistical
> > signifance of the difference between groups for same variables on the
> > tables? I looked through the help file for command table and
> > did not find
> > such options. Do I need to use command ttest for each group
> > and for each
> > variable and then manually indicate the statistical
> > significance on the table?
>
> Occasionally there are options that are not documented. In the
> case of -table- no such option exists. I don't know how a set of
> results for all possible pairwise t tests would be compatible
> with the table structure you seek and in any case it would be
> very poor statistical practice, especially as you seem most
> interested in getting at the significance level. You need
> to read up on problems of multiplicity in hypothesis testing.
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
