Home > Informatics >

Technical Specifications

GCE Data Structure Conceptual Diagram

GCE Data Structure conceptual diagram

GCE Data Structure Specification (version 1.1)

GCE Data Structures are multidimensional MATLAB structure arrays designed to store fully-documented tabular data sets.  The structures are composed of 17 named fields, each containing an individual value, array, or other multidimensional array according to the specification table below.  For more information on working with this specification, see the GCE Data Toolbox description page.

Field Content Type Description
version nx1 cell array of strings GCE Data Structure version (used for validation)
title character array Title of the overall data set
metadata nx3 cell array of strings Parseable array of general data set metadata (i.e variable-length array of metadata category names, field names, field values)
datafile nx2 cell array Names and table sizes of all data sets added to the structure
createdate character array Date and time the data structure was created
editdate character array Date and time the structure was last edited
history nx2 cell array of strings Processing history of the data structure (list of dates and descriptions of each operation performed on the data structure)
name 1xm cell array of strings Name of each data column
description 1xm cell array of strings Description of each data column
units 1xm cell array of strings Units for values in each data column
datatype 1xm cell array of strings Physical data type of each column (i.e. storage type, e.g. 'f' for floating-point, 'e' for exponential, 'd' for decimal/integer, 's' for string)
variabletype 1xm cell array of strings Variable type of each column (i.e. basic semantic type, e.g. 'data', 'calculation', 'nominal', 'logical', 'datetime', 'ordinal', 'code', 'coord', 'text')
numbertype 1xm cell array of strings Numerical data type of each column (e.g. 'continuous', 'discrete', 'angular', 'none' for non-numeric)
precision 1xm array of integers Decimal places to display for each column (0 for non-numeric)
values 1xm cell array Data values (each cell contains a matching "column" of data, as an nx1 numerical array or nx1 cell array of strings, to form a virtual data table)
criteria 1xm cell array of strings QA/QC flag criteria expressions for each column
flags 1xm cell array Arrays of flag characters (each cell is empty or contains an nxm character array of flags, matching the length of the corresponding value column)

GCE Stat Structure Specification (version 1.1)

GCE Stat Structures are multi-dimensional MATLAB® structure arrays designed to store statistical summary information for a single GCE Data Structure.  Stat structures are composed of 27 named fields, each containing an individual value, array, or other multidimensional array according to the specification table below.  Note that these structures are static, and only export and viewing operations are supported by the GCE Data Toolbox.

Field Content Type Description
version nx1 cell array of strings GCE Data Structure version (used for validation)
title character array Title of the overall data set (derived from data structure)
metadata nx3 cell array of strings Parseable array of general data set metadata (i.e. variable-length array of metadata category names, field names, field values)
history nx2 cell array of strings Processing history of the data structure (list of dates and functions performed; continued from data structure history)
analysisdate character array Date and time the stat structure was created
name 1xm cell array of strings Name of each column (from data structure)
description 1xm cell array of strings Descriptions of each column (from data structure)
units 1xm cell array of strings Units of values in each column (from data structure)
datatype 1xm cell array of strings Physical data type of each column (from data structure)
variabletype 1xm cell array of strings Variable type of each column (from data structure)
numbertype 1xm cell array of strings Numerical data type of each column (from data structure)
precision 1xm array of integers Decimal places to display for each column (from data structure)
criteria 1xm cell array of strings Flag criteria expressions for each column (from data structure)
group 1x4 cell array Name, units, data type, and precision of the grouping variable (blanks if ungrouped)
groupvalue nx1 array of numbers or
nx1 cell array of strings
Group values (empty cell array if ungrouped)
observations nxm array Total observations for each column (all data types)
missing nxm array Total number of missing values for each column (all data types)
valid nxm array Total number of non-missing observations for each column (all data types)
flagged nxm array Total flagged values for each column (all data types)
min nxm array Column or group minima (if numeric data type, NaN otherwise)
max nxm array Column or group maxima (if numeric data type, NaN otherwise)
total nxm array Column or group total (if numeric data type, NaN otherwise)
median nxm array Column or group median (if numeric data type, NaN otherwise)
mean nxm array Column or group mean (data type = 'f' or 'e', variable type 'data' or 'calculation')
stddev nxm array Column or group sample standard deviation (data type = 'f' or 'e', variable type 'data' or 'calculation')
se nxm array Column or group standard error (data type = 'f' or 'e', variable type 'data' or 'calculation')
   Data Storage
LTER
NSF

This material is based upon work supported by the National Science Foundation under grants OCE-9982133, OCE-0620959 and OCE-1237140. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.