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NeXtMidas Training
File Handlers
Lab 1
File Format
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- Objective:
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For this lab you will be creating a file handler for a simple file type.
At the end of this lab it will be possible to STATUS the new file
type and read/write it.
- File format:
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The file format we will be supporting will be the ORANGE file format
(.orange). ORANGE files hold linearly-sampled data similar to
a Type 1000 BLUE file.
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ORANGE files have a 24 byte header followed by the data. All data in the
file is either ScalarLong (SL) or SclarFloat (SF).
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The file header contained the following fields:
Byte Offset | Type | Name | Default Value | Description |
0 | char[6] | Version | "ORANGE" | File version always "ORANGE". |
7 | char[2] | Format | "SL" | Data format ("SL" or "SF"). |
8 | double | XStart | 0.0 | X-axis start value. |
16 | double | XDelta | 1.0 | X-axis delta value. |
Note that char[6] and char[2] reference Strings of length
6 and 2 respectively.
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The data portion immediately follows the header (i.e. starting at byte offset 24). The
data portion extends to the end of the file (unlike a BLUE file there is no "extended
header" at the end of the file).
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All information in the header, and all of the data is stored using little-endian byte
order (EEEI). (For those unfamilar with byte ordering, think of it as
defining whether you write left-to-right or right-to-left.)
- continued on next page
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