{smcl}
{* 14mar2008}{...}
{cmd:help mif2dta}{right:Version 2.0.0}
{hline}

{title:Title}

{p 4 11 2}
{hi:mif2dta} {hline 2} Converts MapInfo Interchange Format files 
   to Stata datasets{p_end}


{marker syntax}{title:Syntax}

{p 8 15 2}
{cmd:mif2dta} {helpb using} {it:miffile} 
[{cmd:,}
{help mif2dta##options1:{it:options}}]


{synoptset 35 tabbed}{...}
{marker options1}{synopthdr:{help mif2dta##options2:options}{col 41}}
{synoptline}
{syntab: Main}
{p2coldent :* {opt t:ype(spobj)}}spatial object type, where {it:spobj}
   is one of the following: {cmd:polygon}, {cmd:polyline},
   {cmd:point}{p_end}
{synopt :{cmdab:genid(}{help newvar:{it:idvar}}{cmd:)}}generate spatial
   object id variable {it:idvar}{p_end}
{synopt :{opt genc:entroids(stub)}}generate polygon centroid variables
   {cmd:x}{it:stub} and {cmd:y}{it:stub}{p_end}

{syntab: Saving results}
{p2coldent :* {opt a:ttributes(attrfile)}}save spatial object attributes to
   Stata dataset {it:attrfile}{p_end}
{synopt :{opt c:oordinates(coordfile)}}save spatial object coordinates to
   Stata dataset {it:coordfile}{p_end}
{synopt :{opt replace}}overwrite datasets {it:attrfile} and {it:coordfile} if
   already existing{p_end}
{synoptline}
{p 4 6 2}* Required option{p_end}


{marker desc}{title:Description}

{pstd} {cmd:mif2dta} converts MapInfo Interchange Format files (aka MIF files)
       to Stata datasets usable by {cmd:spmap}, a user-written Stata program
       {hline 1} available from the SSC Archive {hline 1} aimed at visualizing
       spatial data.

{pstd} Any logical MIF file {it:miffile} consists of two physical files that,
       for the purposes of {cmd:mif2dta}, must reside in the same directory:

{phang2}{space 1}o{space 2}{it:miffile}.mif contains the coordinates that
                           define the shape/location of {it:n} spatial
                           objects of a given type. The current version of
                           {cmd:mif2dta} supports three types of spatial
                           objects: polygons, polylines, and
                           points. Moreover, {cmd:mif2dta} can handle only
                           MIF files that store spatial objects of a single
                           type.{p_end}

{phang2}{space 1}o{space 2}{it:miffile}.mid contains the values taken
                           on by one or more attributes of the spatial
                           objects.{p_end}

{pstd}{cmd:mif2dta} converts the logical MIF file {it:miffile} specified by
      the user (see {help mif2dta##syntax:syntax diagram} above) into one or
      two Stata datasets, depending on the type of spatial objects stored
      in {it:miffile}.

{pstd}When option {cmd:type(polygon)} or {cmd:type(polyline)} is specified,
      {cmd:mif2dta} creates two Stata datasets:
      
{phang2}{space 1}o{space 2}The attributes dataset {it:attrfile}, which
      contains the attributes of the spatial objects stored in {it:miffile}
      plus three variables optionally generated by {cmd:mif2dta}: the spatial
      object id variable {it:idvar} and {hline 1} when option
      {cmd:type(polygon)} is specified {hline 1} the polygon centroid
      variables {cmd:x}{it:stub} and {cmd:y}{it:stub}. It should be noted
      that, though not required, in most cases the creation of the spatial
      object id variable {it:idvar} is desirable, since it allows to establish
      a proper link between the attributes dataset and the coordinates
      dataset.{p_end}

{phang2}{space 1}o{space 2}The coordinates dataset {it:coordfile}, which
      contains the coordinates of the spatial objects stored in
      {it:miffile}. Expressly, {it:coordfile} includes three variables: _ID, a
      numeric variable that uniquely identifies the spatial objects; _X, a
      numeric variable containing the {it:x}-coordinate of the nodes making up
      the spatial objects; and _Y, a numeric variable containing the
      {it:y}-coordinate of the nodes making up the spatial objects.{p_end}

{pstd}In turn, when option {cmd:type(point)} is specified, {cmd:mif2dta}
      creates only the attributes dataset {it:attrfile}, which contains
      both the attributes of the points stored in {it:miffile} and the
      following three variables automatically generated by
      {cmd:mif2dta}: _ID, a numeric variable that uniquely identifies the
      points; _X, a numeric variable containing the {it:x}-coordinate of
      the points; and _Y, a numeric variable containing the {it:y}-coordinate
      of the points.{p_end}


{marker options2}{title:Options}

{dlgtab:Main}

{phang}
{opt type(spobj)} specifies the type of spatial objects stored in
   file {it:miffile}.

{phang2}{cmd:type(polygon)} specifies that {it:miffile} stores
   a set of polygons.{p_end}

{phang2}{cmd:type(polyline)} specifies that {it:miffile} stores
   a set of polylines.{p_end}

{phang2}{cmd:type(point)} specifies that {it:miffile} stores
   a set of points.{p_end}

{phang}
{cmdab:genid(}{help newvar:{it:idvar}}{cmd:)} applies only when option
   {bf:type(polygon)} or {bf:type(polyline)} is specified. It requests
   that a new numeric variable {it:idvar} be generated and added to the
   attributes dataset {it:attrfile}, where it will uniquely identify
   the spatial objects stored in file {it:miffile}. The values taken on
   by variable {it:idvar} will correspond to the values taken on by
   variable _ID in the coordinates dataset {it:coordfile}.

{phang}
{opt gencentroids(stub)} applies only when option {bf:type(polygon)} is
   specified. It requests that the coordinates of the centroids of the
   polygons stored in file {it:miffile} be computed, saved in variables
   {cmd:x}{it:stub} and {cmd:y}{it:stub}, and added to the attributes
   dataset {it:attrfile}. When this option is specified, option
   {opt genid(idvar)} is required as well.

{dlgtab:Saving results}

{phang}
{opt attributes(attrfile)} requests that the attributes of the spatial
   objects stored in file {it:miffile} be saved to Stata dataset
   {it:attrfile}.

{phang}
{opt coordinates(coordfile)} applies only when option {bf:type(polygon)}
   or {bf:type(polyline)} is specified. It requests that the coordinates
   of the spatial objects stored in file {it:miffile} be saved to Stata
   dataset {it:coordfile}.

{phang}
{opt replace} requests that datasets {it:attrfile} and {it:coordfile} be
   overwritten if already existing.


{title:Examples}
{cmd}
    . mif2dta using Canada-Provinces, type(polygon) genid(id)      ///
        gencentroids(_coord) attributes(CaProv-Attributes)         ///
        coordinates(CaProv-Coordinates)

    . mif2dta using Canada-Rivers, type(polyline) genid(rivid)     ///
        a(CaRivers-Attributes) c(CaRivers-Coordinates)

    . mif2dta using Canada-Cities, type(point) a(CaCities.dta)   ///
        replace


{title:Acknowledgments}

{p 4 4 2} {txt}I wish to thank Kevin Crow for writing {cmd:shp2dta}, which
   motivated the revision of {cmd:mif2dta}.


{title:Author}

{p 4} Maurizio Pisati {p_end}
{p 4} Department of Sociology and Social Research {p_end}
{p 4} University of Milano Bicocca - Italy {p_end}
{p 4} {browse "mailto:maurizio.pisati@unimib.it":maurizio.pisati@unimib.it}


{title:Also see}

{psee}
Online:  {helpb shp2dta} (if installed), {helpb spmap} (if installed)
{p_end}