mf_rows.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}
{* 15mar2004}{...}
{cmd:help mata rows()}
{hline}
{* index rows()}{...}
{* index cols()}{...}
{* index length()}{...}
{* index length}{...}

{title:Title}

{p 4 4 2}
{bf:[M-5] rows() -- Number of rows and number of columns}


{title:Syntax}

{p 8 8 2}
{it:real scalar}
{cmd:rows(}{it:transmorphic matrix P}{cmd:)}

{p 8 8 2}
{it:real scalar}
{cmd:cols(}{it:transmorphic matrix P}{cmd:)}

{p 8 8 2}
{it:real scalar}
{cmd:length(}{it:transmorphic matrix P}{cmd:)}


{title:Description}

{p 4 4 2}
{cmd:rows(}{it:P}{cmd:)} returns the number of rows of {it:P}.

{p 4 4 2}
{cmd:cols(}{it:P}{cmd:)} returns the number of columns of {it:P}.

{p 4 4 2}
{cmd:length(}{it:P}{cmd:)} returns 
{cmd:rows(}{it:P}{cmd:)}*{cmd:cols(}{it:P}{cmd:)}.


{title:Remarks}

{p 4 4 2}
{cmd:length(}{it:P}{cmd:)}
is typically used with vectors, as in 

	{cmd:for (i=1; i<=length(x); i++) {c -(}}
		... {cmd:x[i]} ...
	{cmd:{c )-}}


{title:Conformability}

    {cmd:rows(}{it:P}{cmd:)}, {cmd:cols(}{it:P}{cmd:)}, {cmd:length(}{it:P}{cmd:)}:
		{it:P}:  {it:r} {it:x} {it:c}
	   {it:result}:  1 {it:x} 1


{title:Diagnostics}

{p 4 4 2}
{cmd:rows(}{it:P}{cmd:)}, {cmd:cols(}{it:P}{cmd:)}, and 
{cmd:length(}{it:P}{cmd:)} return a result that is
greater than or equal to zero.


{title:Source code}

{p 4 4 2}
Functions are built-in.


{title:Also see}

{p 4 13 2}
Manual:  {hi:[M-5] rows()}

{p 4 13 2}
Online:  help for 
{bf:{help m4_utility:[M-4] utility}}
{p_end}