Changes between Version 3 and Version 4 of Tiling
- Timestamp:
- Dec 17, 2012, 1:59:25 PM (12 years ago)
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Tiling
v3 v4 36 36 The resulting layout of the array as stored in the database is shown on the below image. 37 37 38 [[Image(tiling_regular_[0-99 ,0-49]_index_rc_index.png)]]38 [[Image(tiling_regular_[0-99_0-49]_index_rc_index.png)]] 39 39 40 40 === Aligned tiling === … … 54 54 Note that at the edge tile domain will be automatically aligned to the global array bound. No index is specified as by default the [#Rtree R+ tree index] is used, which is perfectly suitable for this tiling scheme. 55 55 56 [[Image(tiling_aligned_[0-29 ,0-133]_tile_size_10000.png)]]56 [[Image(tiling_aligned_[0-29_0-133]_tile_size_10000.png)]] 57 57 58 58 Tile configuration with non-fixed limits indicates a preference to have tiles span along some directions, e.g. the below results in tiles as large as possible along the first dimension (tile domains [ 0:299, 0:43 ]): … … 65 65 }}} 66 66 67 [[Image(tiling_aligned_[0- *,0-43]_tile_size_40000.png)]]67 [[Image(tiling_aligned_[0-_0-43]_tile_size_40000.png)]] 68 68 69 69 If fixed tiles are required, regular tiling can be imitated by setting tile size to match the tile configuration. For example, if the tile configuration is [ 0:29, 0:39, 0:59] and cell size is 2, then the tile size should be set to 144000. This will also result in more efficient computation of the tiling since the given tile configuration is used unchanged if `90% * tile_size < size of tile_config < tile_size` (i.e., no computation is necessary). This applies equally to tile configurations with non-fixed limits. … … 77 77 The difference to regular tiling is that the tiles at the borders will be adjusted to fit in the domain in this case. 78 78 79 [[Image(tiling_aligned_[0- *,0-43]_tile_size_40000.png)]]79 [[Image(tiling_aligned_[0-29_0-133]_tile_size_4020.png)]] 80 80 81 81 === Directional tiling === … … 93 93 tiling directional [0,100,299],[0,50,80,100,200,299] 94 94 }}} 95 [[Image(tiling_directional_[0 ,100,299],[0,50,80,100,200,299].png)]]95 [[Image(tiling_directional_[0_100_299]_[0_50_80_100_200_299].png)]] 96 96 97 97 This gives a preference to the second direction, i.e. tiles will be as large as possible in this direction: … … 102 102 tiling directional [0,100,299],[*] 103 103 }}} 104 [[Image(tiling_directional_[0 ,100,299],[*].png)]]104 [[Image(tiling_directional_[0_100_299]_[].png)]] 105 105 106 106 Finally, specifying a with subtiling allows to respect the tile size and break between the given limits if the tile configuration in order to match tiles to the given tile size: … … 113 113 tile size 30000 114 114 }}} 115 [[Image(tiling_directional_[0 ,100,200,299],[*]_with_subtiling_tile_size_30000.png)]]115 [[Image(tiling_directional_[0_100_200_299]_[]_with_subtiling_tile_size_30000.png)]] 116 116 117 117 === Tiling areas of interest === … … 125 125 tiling area of interest [100:299,0:199],[0:49,0:49] 126 126 }}} 127 [[Image(tiling_area_of_interest_[100-299 ,0-199],[0-49,0-49].png)]]127 [[Image(tiling_area_of_interest_[100-299_0-199]_[0-49_0-49].png)]] 128 128 129 129 Without specifying a tile size, the tiles (besides those specified in the tiling configuration) will be as large as possible. Specifying a tile size will limit those other tiles, but it may also limit the tiles for the interesting areas. Several tile size limitation options allow to have a more precise control over this: … … 142 142 ''indexName'': '''rpt_index''' 143 143 144 General index structure that works with all tiling schemes. 145 144 146 === Directory index === 145 147 ''indexName'': '''d_index''' 146 148 149 Directory of interval objects index like an R+ tree works with all tiling schemes. 150 147 151 === Regular computed index === 148 152 ''indexName'': '''rc_index''' 153 154 Special index that works only with regular tiling. It should provide speed advantage over any other index, however there is a [#254 bug] at the moment.