I have difficulty with simple math

git-svn-id: http://svn.osgeo.org/postgis/trunk@8601 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/using_raster_dataman.xml b/doc/using_raster_dataman.xml
index 39bc424ad0ee96103147199d62010acbe656b838..2f439ac824c303dd6b8adca0b348a51e3d39f667 100644 (file)
--- a/doc/using_raster_dataman.xml
+++ b/doc/using_raster_dataman.xml
@@ -493,7 +493,7 @@ Available GDAL raster formats:
                                        <para><varname>overview_factor</varname> - this is the pyramid level of the overview table.  The higher the number the lower the resolution of the table.
                                        raster2pgsql if given a folder of images, will compute overview of each image file and load separately.  Level 1 is assumed and always the original file. Level 2 is
                                        will have each tile represent 4 of the original.  So for example if you have a folder of 5000x5000 pixel image files that you chose to chunk 125x125, for each image file your base table will
-                                               have 5000/125 records = 40, your (l=2) <varname>o_2</varname> table will have ceiling(40/Power(2,2)) = 10 rows, your (l=3) <varname>o_3</varname> will have ceiling(40/Power(2,3) ) = 5 rows.
+                                               have (5000*5000)/(125*125) records = 1600, your (l=2) <varname>o_2</varname> table will have ceiling(1600/Power(2,2)) = 400 rows, your (l=3) <varname>o_3</varname> will have ceiling(1600/Power(2,3) ) = 200 rows.
                                                If your pixels aren't divisible by the size of your tiles, you'll get some scrap tiles (tiles not completely filled).  Note that each overview tile generated by raster2pgsql has the same number of
                                                pixels as its parent, but is of a lower resolution where each pixel of it represents (Power(2,overview_factor) pixels of the original).</para>
                                </listitem>