m2_comments.hlp

是一个经济学管理应用软件 很难找的 但是经济学学生又必须用到

{smcl}
{* *! version 1.0.0  24may2005}{...}
{cmd:help m2 comments}
{hline}
{* index comments}{...}

{title:Title}

{p 4 4 2}
{hi:[M-2] comments -- Comments}


{title:Syntax}

	{cmd:/*} {it:enclosed comment} {cmd:*/}

	{cmd://} {it:rest-of-line comment}


{p 4 4 2}
Notes:

{p 8 12 2}
1.  
Comments may appear in do-files and ado-files; they are not allowed 
interactively.  

{p 8 12 2}
2.
Stata's beginning-of-the-line asterisk comment is not allowed in Mata:

		. {cmd:*} {it:valid in Stata but not in Mata}


{title:Description}

{p 4 4 2}
{cmd:/*} and {cmd:*/} and {cmd://} are how you place comments in 
Mata programs.


{title:Remarks}

{p 4 4 2}
There are two comment styles:  {cmd:/*} and {cmd:*/}, and {cmd://}.
You may use one, the other, or both.

{p 4 4 2}
Remarks are presented under the headings 

	{bf:The /* */ enclosed comment}
	{bf:The // rest-of-line comment}


{title:The /* */ enclosed comment}

{p 4 4 2}
Enclosed comments may appear on a line:

	{cmd:/*} {it:What follows uses an approximation formula:} {cmd:*/}

{p 4 4 2}
Enclosed comments may appear within a line and even in the middle of a
Mata expression:
             
	{cmd:x = x + /*}{it:left-single quote}{cmd:*/ char(96)}

{p 4 4 2}
Enclosed comments may themselves contain multiple lines

	{cmd:/*}
	    {it:We use the approximation based on sin(x) approximately}
            {it:equaling x for small x; x measure in radians}
	{cmd:*/}

{p 4 4 2}
Enclosed comments may be nested, which is useful for commenting out code that
itself contains comments:

	{cmd:/*}
	{it:for (i=1; i<=rows(x); i++) {c -(}}        {cmd:/*} {it:normalization} {cmd:*/}
		{it:x[i] = x[i] :/ value[i]}
	{it:{c )-}}
	{cmd:*/}


{title:The // rest-of-line comment}

{p 4 4 2}
The rest-of-line comment may appear by itself on a line

	{cmd://} {it:What follows uses an approximation formula:}

{p 4 4 2}
or it may appear at the end of a line:

	{cmd:x = x + char(96)      //} {it:append single quote}

{p 4 4 2}
In either case, the comment concludes when the line ends.


{title:Also see}

{p 4 13 2}
Manual:  {hi:[M-2] comments}  (forthcoming)

{p 4 13 2}
Online:  help for 
{bf:{help m2_intro:[M-2] intro}}
{p_end}