mf_sign.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 sign()}
{hline}
{* index sign()}{...}
{* index dsign()}{...}
{* index quadrant()}{...}

{title:Title}

{p 4 4 2}
{bf:[M-5] sign() -- Sign and complex quadrant functions}


{title:Syntax}

{p 8 12 2}
{it:real matrix}{bind:     }{cmd:sign(}{it:real matrix R}{cmd:)}

{p 8 12 2}
{it:real matrix}{bind: }{cmd:quadrant(}{it:complex matrix Z}{cmd:)}


{title:Description}

{p 4 4 2}
{cmd:sign(}{it:R}{cmd:)} returns the elementwise sign of {it:R}.  
{cmd:sign()} is defined

	argument range      {cmd:sign(}{it:arg}{cmd:)}
	{hline 31}
        {it:arg} >= .                .
        {it:arg} <  0               -1
        {it:arg} == 0                0
        {it:arg} >  0                1
	{hline 31}

{p 4 4 2}
{cmd:quadrant(}{it:Z}{cmd:)} returns a real matrix recording the 
quadrant of each complex entry in {it:Z}.  
{cmd:quadrant()} is defined

	  argument range
        Re({it:arg})    Im({it:arg})      {cmd:quadrant(}{it:arg}{cmd:)}
	{hline 37}
	Re >= .                        .
        Re == 0    Im == 0             .
        Re >  0    Im >= 0             1
        Re <= 0    Im >  0             2
        Re <  0    Im <= 0             3
        Re >= 0    Im <  0             4
	{hline 37}
        {cmd:quadrant(}1+0i{cmd:)}==1, {cmd:quadrant(}-1+0i{cmd:)}==3
        {cmd:quadrant(}0+1i{cmd:)}==2, {cmd:quadrant(} 0-1i{cmd:)}==4


{title:Conformability}

    {cmd:sign(}{it:R}{cmd:)}:
	{it:R}:  {it:r x c}
   {it:result}:  {it:r x c}

    {cmd:quadrant(}{it:Z}{cmd:)}:
	{it:Z}:  {it:r x c}
   {it:result}:  {it:r x c}


{title:Diagnostics}

{p 4 4 2}
{cmd:sign(}{it:R}{cmd:)} returns missing when {it:R} is missing.

{p 4 4 2}
{cmd:quadrant(}{it:Z}{cmd:)} returns missing when {it:Z} is missing.


{title:Source code}

{p 4 4 2}
{view quadrant.mata, adopath asis:quadrant.mata};
{cmd:sign()} is built-in.


{title:Also see}

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

{p 4 13 2}
Online:  help for 
{bf:{help mf_dsign:[M-5] dsign()}};
{bf:{help m4_scalar:[M-4] scalar}}
{p_end}