AAIGRID - error calculating yllcorner in ascii header

[jdemone]

There is an error in the creation of the header in the AAIGRID format. 'yllcorner' is calculated using the dx instead of the dy. A proposed patch is attached.

[jdemone]

proposed patch

[warmerdam]

Mateusz,

Could you look into this? I have a vague recollection that this may have been fixed since 1.4.1.

[mloskot]

As I see, only half of the fix (line 816 in r10146) have been applied since 1.4.1.

[mloskot]

I've applied the second part of the fix (r12453).

Frank, Do we have any aaigrid datasets with features specific to Golden Surfer, that we could add to the autotest?

[mloskot]

I ported the fix to stable branch 1.4 (r12461)

[warmerdam]

The applied patch is incorrect. It computes YLLCORNER improperly. In normal cases adfGeoTransform[5] is negative while adfGeoTransform[1] was positive. This basically means that yllcorner is written as being as far above the top left corner as it ought to be below the top left corner.

        sprintf( szHeader, 
                 "ncols        %d\n" 
                 "nrows        %d\n"
                 "xllcorner    %.12f\n"
                 "yllcorner    %.12f\n"
                 "dx           %.12f\n"
                 "dy           %.12f\n", 
                 nXSize, nYSize, 
                 adfGeoTransform[0], 
                 adfGeoTransform[3] - nYSize * adfGeoTransform[5],
                 adfGeoTransform[1],
                 fabs(adfGeoTransform[5]) );

[warmerdam]

Fixed in trunk (r13561), 1.5 (r13562) and 1.4 (r13563).

Added test in test suite (r13564).