newvarlist.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}
{* 25mar2005}{...}
{cmd:help newvarlist}
{hline}

{title:Title}

    {hi:[U] 11.4.2 Lists of new variables}


{title:Description}

{pstd}
A {it:newvarlist} is a list of new variables:

{p 8 12 2}
    1.  A {it:newvarlist} can literally be a list of one or more 
        {it:{help newvar:newvars}}, listed after another:

		{cmd:x}
		{cmd:x myvar inc92}

{p 8 12 2}
    2.  You may use a dash to specify a set of variables:

		{cmd:p1-p90}{col 43}(means {cmd:p1 p2} ... {cmd:p90})
		{cmd:inc90-inc99}{col 43}(means {cmd:inc90 inc91} ... {cmd:inc99})

{p 8 12 2}
    3.  You may specify a {it:{help data types:storage type}} of 
	{cmd:int}, 
	{cmd:long}, 
	{cmd:float}, 
	{cmd:double}, 
	or
	{cmd:str}{it:#}
	in front of any element of the list:

		{cmd:double x}
		{cmd:str2 name int myvar double inc92}

{p 8 12 2}
    4.  You may use parentheses to collect groups:

		{cmd:double(x myvar inc92) int(p1-p90)}

{p 12 12 2}
	The parentheses around {cmd:p1-p90} were not necessary, but 
	they make the meaning clearer.

{p 8 12 2}
    5.  When you do not specify the type, the default type -- which is usually
	float -- is assumed:

		{cmd:double x myvar inc92}{col 43}({cmd:myvar} and {cmd:inc92} will be float)

{p 12 12 2}
        The default usually is float, but you can change it to double if you
        wish; see {helpb set type}.

{pstd}
Because the default is float or double, you must specify {cmd:str}{it:#} 
if you want to create a string variable.
Some commands understand {cmd:str} (without the number) and determine 
the length themselves.


{title:Examples}

{phang}{cmd:. input x}

{phang}{cmd:. input x y z}

{phang}{cmd:. input double(x y z)}

{phang}{cmd:. input double(x y) str2 z}

{phang}{cmd:. generate str10 last = substr(name, 1, index(name, ",")-1)}

{phang}{cmd:. generate str last = substr(name, 1, index(name, ",")-1)}


{title:Also see}

{psee}
Manual:  {bf:[U] 11 Language syntax},{break}
{bf:[U] 11.4.2 Lists of new variables}

{psee}
Online:  {help language}, {help varname}, {help newvar}
{p_end}