[R-sig-Geo] Projection question...

[Jonathan Greenberg]

Folks:

Robert has a version of this email concerning the implementation in
raster, but I'm wondering if there's something going on with rgdal or
proj?  Can anyone think of a reason why reprojecting a file of North
America with the following projection info:

"+proj=lcc +lat_1=50 +lat_2=50 +lat_0=50 +lon_0=-107 +x_0=5632642
+y_0=4612546 +ellps=WGS84"

to

"+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0"

would be losing all data north of latitude = 46.63769 (even if there
is clearly data above this latitude)?  Here's the raster info of the
file I'm trying to reproject:

> unsynced
class       : RasterLayer
filename    :
nrow        : 277
ncol        : 349
ncell       : 96673
min value   : 0
max value   : 10.1305
projection  : +proj=lcc +lat_1=50 +lat_2=50 +lat_0=50 +lon_0=-107
+x_0=5632642 +y_0=4612546 +ellps=WGS84
xmin        : -16231.49
xmax        : 11313351
ymin        : -16231.5
ymax        : 8976020
xres        : 32462.99
yres        : 32463

A reprojection works in the sense that all data south of latitude =
46.63769 is placed in the right location.  Thoughts?  If there isn't
any obvious answer from this non-code post, I'll append some code
based on a new R package I've been developing so the specific datasets
can be examined more closely.

--j




-- 
Jonathan A. Greenberg, PhD
Assistant Project Scientist
Center for Spatial Technologies and Remote Sensing (CSTARS)
Department of Land, Air and Water Resources
University of California, Davis
One Shields Avenue
Davis, CA 95616
Phone: 415-763-5476
AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307