[R-sig-Geo] your mail

[Roger Bivand]

Dear Md. Moshiur Rahman,

You sent your question to the list administrator, not to the list, so I am 
sending my reply to you and the list.

The simple answer is at the end, but first the complicated answer ...

It would be useful to know which file formats you have access to for your 
data. 

You are correct in saying that the e00 and binary coverages are from
Arc/Info, which many years ago ran only on minicomputers under many
operating systems (Unix, Vax VMS, ...), but never Windows nor Linux (PC
ArcInfo was a different programme running under DOS and 16-bit Windows up
to Windows 95).

ArcView was never more than a "viewer" when first designed, but ESRI - the 
authors of Arc/Info - found that their main customers wanted a 
Windows-based product. For this reason, the newer ArcGIS only runs on 
Windows (I believe), and can use both the legacy e00 and binary coverages 
inherited from Arc/Info, and the simple shapefile format added to ArcView 
as it developed.

The difference between the e00/binary coverage format and shapefiles is
that the former, original Arc/Info files describe the geometry of the
stored objects in a more complicted way. Each line is only stored once,
and the "arc/node" data model builds the lines into more complex
structures - indeed, the product names Arc/Info, ArcView, and ArcGIS refer
directly to the use of this structure. Shapefiles just contain lines or
ring polygons for each object, so contiguous objects have duplicated
border lines in the data.

If the only software you have is ArcView 3.2, then it is possible that the
data representation you have is as shapefiles for ArcView. 

PC ArcInfo 3.5.1 seems to have been discontinued in about 1999, and I
cannot find any documentation on its vector file formats. If PC ArcInfo
3.5.1 can exchange data with ArcView 3.2, then you can move your data to
the shapefile format. There is also a legacy format UNGEN used in
Arc/Info, which may allow you to export data from PC ArcInfo. This format
is described at:

http://www.census.gov/geo/www/cob/ascii_info.html

Since it is an ASCII format, it should be possible to write simple 
functions to read UNGEN (Ungenerate) geometry data into R, but if you have 
not written R functions using connections and readLines() before, you may 
need help.

The simple answer: if you have your data in ArcView already, then I
suggest you read ArcView shapefiles into R, using the maptools package (or
alternatively the shapefiles package), both on CRAN.

Hope this helps,

Roger Bivand


On Mon, 5 Sep 2005, Md. Moshiur Rahman PhD wrote:

> 
> I am a faculty of Department of Statistics, Jahangirnagar University of 
> BANGLADESH.
> 
> Presently I am trying to use RArcInfo in R of Windows version, but the 
> problem I faced is that I cannot import coverage file of Bangladesh. One of 
> my fellow colleague in the Department of Geography are using WINDOWS 
> version ArcView GIS 3.2 and ArcInfo 3.5.1.
> 
> Following lines are from RArcInfo help pages:
> avctoe00                : Converts a ARC/INFO binary coverage into an ESRI 
> E00 file
> e00toavc                : Converts an ESRI E00 file into an Arc/Info V 7.x 
> binary coverage
> read.coverage   :  Function for retrieving basic data from a given coverage
> 
> My colleague informed me that he cannot make ESRI E00 file or ARC/INFO 
> binary coverage in Windows version of ArcView GIS 3.2 and ArcInfo 3.5.1. He 
> also told me that E00 and Arc/Info V 7.x binary coverage are of Unix or 
> Linux files.
> 
> I will be ever grateful if you could please let me know the following at 
> your earliest conveniences:
>          1. How can I make ESRI E00 file in Windows computer
>           2. How can I make ARC/INFO binary coverage in Windows computer
> If I can make E00 file or a coverage, I think I can then use avctoe00, 
> e00toavc and read.coverage
> 
> Can I do above matter in windows computer. Actually I already spent more 
> that one months in this  matter but I could not success.
> 
> I am looking forward for your kind email and assistance in this regard.
> Thanking you in advance.
> 
> Sincerely yours
> 
> Md. Moshiur Rahman Ph.D.
> 
> 
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no