QSAS: The QMUL Science Analysis System

Browsing Data Objects

# Contents

- Overview
- Object Browsers
- Time Interval Editor
- Tips/FAQ
- Bugs

# Overview

Double clicking on any object on the QSAS Working List will launch a browser which allows the user to view and edit (change, delete or create) data and metadata. Highlighting an object on the working list and selecting New Object from the right button menu or Edit menu on the Main Window will also launch the edit browser for that object.

Each data type has its own specific browser, and the appropriate browser will be launched for the object selected. The browsers display a list of any cross references attached to the object (such as attributes) and double clicking an item in this list will in turn launch the appropriate browser for it. Metadata are stored as qsas data objects and the same object types are available for attributes as for data.

If the object name is changed in an Object Browser then this object will be saved as a new object with this name. The data and all metadata are copied to the new object. The name of an object may only be changed using the Rename Object window which can be launched from the Edit menu or right button menu on the QSAS Main Window.

# Object Browsers

Each browser has a top field showing the current name of the object on the working list. For series there will be a field showing the currently displayed record - the may be changed by typing in the field or by using the arrows on either side. The panel below will differ for each data type, but a single current value is always shown for the selected element. In the example above of a vector time series the value field is accompanied by a field showing the time tag for that value and an index display which shows the currently selected component in the vector. This may be changed by typing directly in the component field or using the arrows either side. Objects with higher dimensionality will have index counters for each dimension in the data object.

It is not possible to increment the indices beyond the valid range for the object.

If the value or time fields are edited the save edits and save as buttons become active. These allow the changes to be saved to the object or to a new object respectively.

A right hand panel is always present, and will show all the attributes (metadata) associated with this object. double-clicking on one of the items in this list will launch the equivalent editor for this metadata. Changing the values in this editor will change the metadata attachyed to the object. The Add metadata button will launch a selection dialogue to choose the data type of the new metadata object, and this in turn launches an empty editor of the appropriate type. Time tags may similarly be added to some objects using the Add time tags button.

The View Source Files button will launch a dialogue showing all the data files that held the input data - for direct import this is a single file, for the data selector this may be a lsit of files which were concatenated, and for an object produced internally in qsas this will be empty. When a file name is selected from the list, QSAS will attempt to open it with the direct import browser to allow browsing of the global attributes in the file. Global attributes are not loaded into QSAS with the data and are not available internally. If fill values are stripped from an imported object this file browse facility can also be used to compare the data within QSAS with the data in the file. Note that if Fill values are stripped then any array with one or more fill values will be rejected, and in some products this means that valid data may still be available. Stripping of Fill values can be turned on/off with the toggle on the QSAS Main Window.

# Time Interval Editor

Time Intervals have their own specific time interval editor which is described separately.

# Tips/FAQ

- Double clicking an item in a list will always launch an editor of some sort. In the Working List, Direct Import and any Object Editor itself, this will launch the appropriate object editor. In other lists it will launch a window allowing the link to the object on the working list to be edited.

# Bugs

- Time tag creation is not yet implemented for most object types

Page created by Tony Allen, csc-support-dl@imperial.ac.uk

Last up-dated: December 2008 A Rochel