Input Data
3.1 Non-spatial Tabular Data
Non-spatial input tables are loaded via the dynamic model configuration file (.sel). Data must be in plain text (ASCII) format as tab-separated columns (.txt files).
- The first row may optionally contain column labels.
- By default, the first column specifies the row index, and column indexing starts at 0 from the second column.
- Files can alternatively be loaded as sequential rows (first row at index 0), with column indexing starting at 0 from the first column.
3.2 Spatial Data
SELES10 supports the following raster formats:
| Format | Notes |
|---|---|
| GeoTiff | Preferred — compresses efficiently, loads efficiently, easily transferred to/from GIS |
| GRASS | Binary, compressed, and ASCII variants supported |
| ARC Grid ASCII | Supported |
| ERDAS | 8- and 16-bit; some support for ARC grid binary |
A raster is a rectangular grid of fixed-size cells, each holding a single value. SELES10 uses a 64-bit (8-byte) machine word, which defines the maximum range of values that can be stored.
Integer vs. Real-value Rasters
Most rasters are integer-valued. Some formats (e.g. ARC Grid ASCII) support floating-point real values. Integer-value grids can represent fixed-point real values by choosing a precision multiplier. For example, to represent two decimal places, store values multiplied by 100 (e.g. 12.34 stored as 1234); divide by 100 when retrieving and multiply by 100 when storing.
Real-value rasters can also be automatically scaled on load via the scenario script (see Scenario Scripts — Load GIS Rasters).
GRASS Raster Files
GRASS stores rasters across several files with the same name in specific directories:
| Directory | Contents |
|---|---|
cell/ | Raster cell data |
cellhd/ | Header information (dimensions, resolution, georeferencing) |
colr/ | Colour lookup table (optional) |
cats/ | Legend / category labels (optional) |
When opening GRASS files in SELES, refer to the file in the cell/ subdirectory. If no colour file is found, SELES uses a built-in algorithm. If a colour file is found, those colours are used for display.
Colour Lookup Table Format
SELES supports a generalised version of the GRASS colour file format. A colour file is a list of raster values followed by RGB triples (each component 0–255). For example, pure red = 255:0:0; dark purple = 180:0:180.
Supported specifications:
| Syntax | Meaning |
|---|---|
#Index : RGB | Set the colour of Index to RGB |
#Index1-#Index2 : RGB | Set all values in range [Index1, Index2] to RGB |
#Index1 : RGB1 #Index2 : RGB2 | Interpolate colours from RGB1 to RGB2 over [Index1, Index2] |
If an index has more than one colour specified, the last one is used. If an index has no colour specified, black is used.
3.3 Legend Files
Legends define named constants associated with raster values. Using legend labels instead of raw numbers improves model readability, reduces errors, and makes models more portable (a legend label can stay the same even if the underlying value changes with different input data).
Legend labels should be simple and contain no spaces or punctuation. See Dynamic Model Configuration — Legends for how to define or load legends in a .sel file.
Two types of legend files in SELES10
1. Legend files (typically stored in a cats/ folder):
A simple list of value–label pairs separated by a colon:
#Number: <Label>
Example:
1: Conifer
2: Deciduous
3: Mixed
2. GeoTiff grids with a category table:
Legends can be embedded in a GeoTiff file's raster attribute table or category table, typically stored in an XML file with the same name prefix but with the suffix .tif.aux.xml.
To attach a legend to a GeoTiff in SELES:
- Create a simple legend file.
- Open the GeoTiff raster view.
- With the raster view active, open the legend file.
- Re-save the GeoTiff.
Verify by closing and re-opening the GeoTiff and opening the Legend view.
Either type of legend file can be loaded in a .sel file, which will define each label as a global constant with the specified numeric value.