{smcl}
{* 06dec2005}{...}
{hline}
help for {hi:insob}
{hline}

{title:Insert empty observations}

{p 8 17 2}
{cmdab:insob:}
{it:nobs}
{it:pos}
[{cmd:,}
    {cmdab:after}
]

{title:Description}

{p 4 4 2}
{cmd:insob} inserts {it:nobs} empty observations before observation number 
{it:pos}.

{title:Options}

{p 4 8 2}
{cmd:after} When the option "after" is specified, the empty observations are inserted 
{it:after} observation number {it:pos} (in stead of before).

{title:Remarks}

{p 4 4 2}
The program works by adding a local variable that fixes the original sort order. After new 
observations have been added, the relative sort order of pre-existing observations is restored 
with empty observations before (after) observation number {it:pos}. This approach can be 
relatively slow for large data files.


{title:Examples}

{p 4 8 2}{cmd:. insob 1 1}              // Inserts one observation at beginning of the dataset

{p 4 8 2}{cmd:. insob 2 _N, after}      // Inserts two observations at end of the dataset


{p 4 4 2}{it:Hint:} {cmd:insob} can be used to create custom LaTeX tables (assuming existing
commands like {cmd:tabstat}, {cmd:est2tex}, or {cmd:textab} are not what you are looking for). 
The following example suggests a procedure to export a matrix {it:mtest} containing four 
columns as a LaTeX table.

{p 4 8 2}{cmd:. drop _all}

{p 4 8 2}{cmd:. svmat mtest}

{p 4 8 2}{cmd:. tostring mtest1 mtest2 mtest3 mtest4, replace force format(%9.2f)}

{p 4 8 2}{cmd:. insob 1 1}                                            // Add row headers

{p 4 8 2}{cmd:. replace mtest1 = "$ V_1 $" in 1}

{p 4 8 2}{cmd:. replace mtest2 = "$ V_2 $" in 1}

{p 4 8 2}{cmd:. replace mtest3 = "$ V_3 $" in 1}

{p 4 8 2}{cmd:. replace mtest4 = "$ V_4 $" in 1}

{p 4 8 2}{cmd:. gen a = "&"}                                          // Column separator

{p 4 8 2}{cmd:. gen e = " \\\\"}                                      // End of row

{p 4 8 2}{cmd:. }// Add tabular environment for use with the LaTeX-package {it:booktabs}

{p 4 8 2}{cmd:. insob 2 1}

{p 4 8 2}{cmd:. replace mtest1 = "\begin{tabular}{rrrr}" in 1}

{p 4 8 2}{cmd:. replace mtest1 = "\toprule\addlinespace[\defaultaddspace]" in 2}

{p 4 8 2}{cmd:. insob 1 4}

{p 4 8 2}{cmd:. replace mtest1 = "\midrule\addlinespace[\defaultaddspace]" in 4}

{p 4 8 2}{cmd:. insob 1 _N, after}

{p 4 8 2}{cmd:. replace mtest1 = "\bottomrule" in l/l}

{p 4 8 2}{cmd:. insob 1 _N, after}

{p 4 8 2}{cmd:. replace mtest1 = "\end{tabular}" in l/l}

{p 4 8 2}{cmd:. outfile mtest1 a mtest2 a mtest3 a mtest4 e using "testtable.tex", noquote replace wide }


{title:Author}

{p 4 4 2}
Bas Straathof, ECIS, Eindhoven University of Technology.  Email
{browse "mailto:bas.straathof@gmail.com":me}
if you observe any problems. Thanks to Nick Cox for substantial improvements.