mf_isreal.hlp

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{smcl}
{* 16mar2005}{...}
{cmd:help mata isreal()}
{hline}
{* index isreal()}{...}
{* index iscomplex()}{...}
{* index isstring()}{...}
{* index ispointer()}{...}

{title:Title}

{p 4 8 2}
{bf:[M-5] isreal() -- Storage type of matrix}


{title:Syntax}

{p 8 8 2}
{it:real scalar}
{cmd:isreal(}{it:transmorphic matrix X}{cmd:)}

{p 8 8 2}
{it:real scalar}
{cmd:iscomplex(}{it:transmorphic matrix X}{cmd:)}

{p 8 8 2}
{it:real scalar}
{cmd:isstring(}{it:transmorphic matrix X}{cmd:)}

{p 8 8 2}
{it:real scalar}
{cmd:ispointer(}{it:transmorphic matrix X}{cmd:)}


{title:Description}

{p 4 4 2}
{cmd:isreal(}{it:X}{cmd:)}
returns 1 if {it:X} is a {cmd:real} and returns 0 otherwise.

{p 4 4 2}
{cmd:iscomplex(}{it:X}{cmd:)}
returns 1 if {it:X} is a {cmd:complex} and returns 0 otherwise.

{p 4 4 2}
{cmd:isstring(}{it:X}{cmd:)}
returns 1 if {it:X} is a {cmd:string} and returns 0 otherwise.

{p 4 4 2}
{cmd:ispointer(}{it:X}{cmd:)}
returns 1 if {it:X} is a {cmd:pointer} and returns 0 otherwise.


{title:Remarks}

{p 4 4 2}
These functions base their results on storage type.
{cmd:isreal()} is not the way to check whether a number is real,
since it might be stored as a complex and yet still be a real number, 
such as 2+0i.  To determine whether {it:x} is real, you want to 
use {cmd:isrealvalues(}{it:X}{cmd:)};  see
{bf:{help mf_isrealvalues:[M-5] isrealvalues()}}.


{title:Conformability}

{p 4 4 2}
{cmd:isreal(}{it:X}{cmd:)},
{cmd:iscomplex(}{it:X}{cmd:)},
{cmd:isstring(}{it:X}{cmd:)},
{cmd:ispointer(}{it:X}{cmd:)}:
{p_end}
		{it:X}:  {it:r x c}
	   {it:result}:  1 {it:x} 1


{title:Diagnostics}

{p 4 4 2}
These functions return 1 or 0; they cannot fail.


{title:Source code}

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


{title:Also see}

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

{p 4 13 2}
Online:  help for 
{bf:{help mf_isrealvalues:[M-5] isrealvalues()}},
{bf:{help mf_eltype:[M-5] eltype()}};
{bf:{help m4_utility:[M-4] utility}}
{p_end}