[R-sig-Geo] Shape file of USA land cover data

[Hodgess, Erin]

Hi

I got the same data set that Milan did and used the raster:

r <- raster("c://goodc//nlcd2006_landcover_4-20-11_se5.img")

and it worked.  When I used gdal, it said that it was too big.

Thanks,
Erin 
PS the plot looks really nice too.

________________________________________
From: r-sig-geo-bounces at r-project.org [r-sig-geo-bounces at r-project.org] on behalf of Michael Sumner [mdsumner at gmail.com]
Sent: Wednesday, December 05, 2012 8:34 PM
To: Milan Sharma
Cc: r-sig-geo at r-project.org
Subject: Re: [R-sig-Geo] Shape file of USA land cover data

It's not a shapefile, and it's not a vector format. It's a gridded
(raster) format. Specifically it's an Erdas Imaging (.img) format:

http://www.gdal.org/frmt_hfa.html

I tried the Hawaii one which is much smaller (2.4Mb) and so more
reasonable to share.

http://gisdata.usgs.gov/TDDS/DownloadFile.php?TYPE=nlcdhi&FNAME=HI_landcover_wimperv_9-30-08_se5.zip

You seem to have found metadata files, but I haven't found what you
presented to us.

I get this:

 list.files()
[1] "hi_landcover_wimperv_9-30-08_se5.img"
[2] "hi_landcover_wimperv_9-30-08_se5.rrd"
[3] "landcov_meta_web_final"

library(raster)
r <- raster("hi_landcover_wimperv_9-30-08_se5.img")
r
class       : RasterLayer
dimensions  : 12618, 19439, 245281302  (nrow, ncol, ncell)
resolution  : 30, 30  (x, y)
extent      : -345945, 237225, 1753875, 2132415  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=aea +lat_1=8.000000000000002 +lat_2=18 +lat_0=3
+lon_0=-157 +x_0=0 +y_0=0 +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m
+no_defs
data source : C:\Users\Michaels\Downloads\HI_landcover_wimperv_9-30-08_se5\hi_landcover_wimperv_9-30-08_se5.img
names       : hi_landcover_wimperv_9.30.08_se5
values      : 0, 95  (min, max)
Raster Attribute Table
     fields :  ID     COUNT  Red Green Blue Land.Cover.Class Opacity
        min :   0         0 0.00  0.00 0.00                        0
        max : 255 221606161 0.98  0.98 0.98   Woody Wetlands       1


You'll have to work through the documentation for rasters to
understand how to work with these data. The raster package requires
rgdal to load this format, and you could do that more directly with

require(rgdal)
r <- readGDAL("hi_landcover_wimperv_9-30-08_se5.img")

though arguably raster is probably a better place to start.

Cheers, Mike.

On Thu, Dec 6, 2012 at 1:10 PM, Milan Sharma <milansharma2012 at yahoo.com> wrote:
> Hi List,
> I  wanted to download national land cover data of USA, 2006 which I could convert to shape file and do analysis. The website is http://www.mrlc.gov/nlcd01_data.php.
>  I got the following 6 files in it:
> 1. appendix1_nlcd2006_scene_list_by_path_row_txt
> 2. appendix1_nlcd2006_scene_list_by_path_zone_txt
> 3. metadata_nlcd2006_lc_4-20-11-txt
> 4. metadata_nlcd2006_lc_4-20-11-se5.ige
> 5. metadata_nlcd2006_lc_4-20-11-se5.img
> 6.metadata_nlcd2006_lc_4-20-11-se5.rrd
>
> I didn't see any shape file in here, or will I get the shape file from any one  the above  file formats?
> (Has anybody in the list downloaded such data?) (or can anybody instruct me of how to get it done?
> Thanks so much for your help,
> Milan
>         [[alternative HTML version deleted]]
>
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>



--
Michael Sumner
Hobart, Australia
e-mail: mdsumner at gmail.com

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