GDF - description

Generic Data Format structure contains 9 variables, where d is the most essential one, because it contains the data which can be further processed. The other variables are used for the correct data description – units, coordinate system, fields etc.

GDF file name following the scheme: GDF_EPISODENAME_file_description.

The structure of Generic Data Format

Variable name

Type

Description

CRS

char

Coordinate Reference System
EPSG code (or local) mapping surveying (http://epsg.io), standard WGS84 (EPSG: 4326). If not applicable input ‘n/a’.

d

struct

The variable containing the data. The data may be as a single variable, a vector or an array. Data name following the scheme: Name_of_parameter or NAME (for shortcuts, chemical formulas etc.)

Description

char

The text description of the data contained in the file

FieldDescription

cell

Description of the fields. An array contains two columns: the first contains the name of the field/column of data, the second contains a description of them. All data must be specified

FieldType

cell

An array contains two columns: the first contains the name of the field/column of data, the second contains the data type number. All data must be specified. The Numbers of Data type:

1 – the real data without limits,

2 – the integer data,

3 – text value,

4 – the real number rounded to 0.1 (shown as 11),

5 – time in Matlab format serial time – the time display format; seconds with accuracy 1/10,

5a - time containing only year value e.g. '2010', the time display format: year '2010'
5b - time containing only year and month value e.g. '2010-01', the time display format: year month e.g. '2010 Jan'
5<pattern> - time read from string with the provided pattern, specified according to the table:

symbols:

year: 'y'

month: 'M'

day: 'd'

hour: 'H'

minute: 'm'

second: 's'

mili- , micro-second: 'S'

examples:

"5yyyy MMM dd HH:mm:ss"

result: "2010 Jan 23 14:15:20"

"5yyyy-MM-dd"

result: "2010-01-23"

"5HH:mm:ss.SSS"

result: "14:15:20.454"

"5HH:mm:ss.SSSSSS"

result: "14:15:20.454323"

6 – the real data display in an engineering manner with one decimal place, e.g.: 3.5E6, (obsolete, recommended 2cd)

7 – the real data display in an engineering manner with two decimal place, (obsolete, recommended 2cd)

bc – (b and c are code digits) the real data is displayed in fix-point manner with at minimum b places before decimal and c decimal place,

e.g. For number 3.149.

10: „3”

11: „3.1”

12: „3.15”

20: „03”

23: „03.149”

1bc– the same manner as bc, but with place for a sign (space for sign „+”, sign ‘-’ for sign „-”),

2cd– (c and d are code digits), the real data is displayed in an engineering manner, with place for a sign (space for sign „+”, sign ‘-’ for sign „-”), with c decimal place and exponent expressed by d places. The sign in exponent is always displayed.

e.g. For number 0.001

211: „1.0E-3”

221: „1.00E-3”

212: „1.0E-03”

222: „1.00E-03”

e.g. For number 1000

211: „1.0E+3”

221: „1.00E+3”

212: „1.0E+03”

222: „1.00E+03”

FieldUnit

cell

Description of units for individual data, e.g. m/s. An array contains two columns: the first contains the name of the field/column of data, the second contains the unit. All data must be specified.

FormatName

char

Name of data format GDF (Generic Data Format).

FormatVersion

double

When changing/expansion of the format change its version. It can have one number after the decimal point.

TimeZone

char

Acronym of Time Zone (http://en.wikipedia.org/wiki/List_of_time_zone_abbreviations) from the episode of origin. If not applicable input ‘n/a’.