[R-sig-Geo] Reversed raster after readGDAL()

[Agustin Lobo]

Yes, same problem
Agus

2010/2/10 Paul Hiemstra <p.hiemstra at geo.uu.nl>:
> Hi,
>
> What if you make an spplot, still the same problem?
>
> cheers,
> Paul
>
> Agustin Lobo wrote:
>>
>> Thanks Sarah. But I think that package sp has an specific method of
>> image() for objects SpatialGridDataFrame, which is the class returned
>> by readGDAL(), and this specific method takes care of this problem. Check
>> image.SpatialGridDataFrame in package {sp}
>>
>> Agus
>>
>> 2010/2/10 Sarah Goslee <sarah.goslee at gmail.com>:
>>
>>>
>>> This may well be too simplistic an answer, but it might just be image().
>>>
>>> From the help for image:
>>>    Notice that ‘image’ interprets the ‘z’ matrix as a table of
>>>    ‘f(x[i], y[j])’ values, so that the x axis corresponds to row
>>>    number and the y axis to column number, with column 1 at the
>>>    bottom, i.e. a 90 degree counter-clockwise rotation of the
>>>    conventional printed layout of a matrix.
>>>
>>> x <- matrix(rep(1:10, each=10), nrow=10)
>>> x
>>>     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
>>>  [1,]    1    2    3    4    5    6    7    8    9    10
>>>  [2,]    1    2    3    4    5    6    7    8    9    10
>>>  [3,]    1    2    3    4    5    6    7    8    9    10
>>>  [4,]    1    2    3    4    5    6    7    8    9    10
>>>  [5,]    1    2    3    4    5    6    7    8    9    10
>>>  [6,]    1    2    3    4    5    6    7    8    9    10
>>>  [7,]    1    2    3    4    5    6    7    8    9    10
>>>  [8,]    1    2    3    4    5    6    7    8    9    10
>>>  [9,]    1    2    3    4    5    6    7    8    9    10
>>> [10,]    1    2    3    4    5    6    7    8    9    10
>>> image(x) # not what you might expect
>>> image(t(x)) # this view matches the matrix representation
>>>
>>> What happens if you use plot(mygeotiff) instead of image(mygeotiff)?
>>>
>>> Sarah
>>>
>>> On Wed, Feb 10, 2010 at 11:17 AM, Agustin Lobo <alobolistas at gmail.com>
>>> wrote:
>>>
>>>>
>>>> I think I tripped on this same stone, but cannot find anything in my
>>>> records, perhaps it's on the lost computer.
>>>>
>>>> The file test2.tif was made by plugin Interpolation in QGIS out of a
>>>> vector layer of points with nitrate concentration values, just
>>>> a simple inverse distance method. I think that the author f that
>>>> pluginis Marco Hugentobler (Marco, sorry if it's not you) to whom I'm
>>>> forwarding.
>>>>
>>>> Relevant info from the metadata in QGIS for this raster:
>>>>
>>>> Layer Spatial Reference System:
>>>> +proj=utm +zone=31 +ellps=intl +units=m +no_defs
>>>>
>>>> Origin
>>>> 424389,4.68549e+06
>>>>
>>>> Pixel Size:
>>>> 279.887,-279.887
>>>>
>>>> NW corner in QGIS (interactive):424388.820,4685490.931
>>>> SW corner in QGIS (interactive):424389.122,4635951.740
>>>>
>>>> Image with grid:
>>>> http://sites.google.com/site/eospansite/dummy/test2gridqgis.jpg
>>>>
>>>> The weird thing is that QGIS uses gdal to read the geotif files.
>>>>
>>>>
>>>> Agus
>>>>
>>>>
>>>
>>> --
>>> Sarah Goslee
>>> http://www.functionaldiversity.org
>>>
>>>
>>
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>
>
> --
> Drs. Paul Hiemstra
> Department of Physical Geography
> Faculty of Geosciences
> University of Utrecht
> Heidelberglaan 2
> P.O. Box 80.115
> 3508 TC Utrecht
> Phone:  +3130 274 3113 Mon-Tue
> Phone:  +3130 253 5773 Wed-Fri
> http://intamap.geo.uu.nl/~paul
>
>