EMME Binary Matrix (.mtx)
Overview
The .mtx file format is used in GTAModel V4 to store matrix data
in a compact form that is extremely quick to write and load.
Additionally, the format also contains a copy of the zone system
allowing it to be checked first before loading in order to weed out
a large number of potential errors.
The TMGToolbox contains two tools that allow for the importing and exporting of these files to and from EMME.
There is also an alternative extension .mtx.gz which can be loaded in with version 1.10+ of
the TMGToolbox and XTMF. The .mtx.gz format is compressed using the GZip algorithm but otherwise
idential to the original .mtx format.
File Specification
| Component | DataType | Description |
|---|---|---|
| Magic Number | uint32 | 0xC4D4F1B2 |
| Version Number | int32 | 1 |
| Type | int32 | float32 = 1, float64 = 2, int32 = 3, int64 = 4 |
| Dimensions | int32 | Scalar = 0, Vector = 1, Matrix = 2 |
| IndexSize | int32 | The size per dimension of the Vector. A matrix will have 2 values. |
| Zone Number | int32 | For each dimension an index size worth of zone numbers |
| Raw Data | Depends on Type | One value per expected cell |
You can review example code here for reading and writing this file format.