# QSAS: The QMUL Science Analysis System

# Analysis

## Contents:

- Overview

- Purpose
- User Interface

- Joining Time Series
- Arithmetic
- Plug-ins
- Tips/FAQ
- Bugs

## Overview

### Purpose

QSAS enables the user to perform various kinds of analysis and manipulation of data. In all cases, the operations are performed on objects held on the QSAS Working List, and the results of the analysis are, in general, returned as new objects on the Working List from which they may be further manipulated, plotted, or exported.

QSAS currently supports three types of manipulation:

1. Specialised analysis routines requiring specific user interfaces (at present, only one such routine is provided and performs a join of two or more time series onto a common set of time tags)
2. General arithmetic operations, including +, -, x, /, and various vector operations. These are sufficiently simple to utilise the generic plug-in interface
3. Plug-ins, which enable user-written routines to be loaded dynamically in order to perform analysis functions. The QSAS team provides an increasing suite of plug-ins, some of which include specialised graphics.

### User Interface

Analysis routines are invoked from the Analysis pull-down menu found on the QSAS Main Window. The specialised and artihmetic routines are listed there. An entry "Plug-ins ..." pops up a file selection widget which is used to locate the "template" (*.qtpl) file in which the inputs and outputs of the plug-in routine are described. Once an analysis routine or template is selected, a graphical user interface is opened. Input objects can be drag'n'dropped from the Working List or typed manually into the boxes provided. Outputs can be renamed as required. In the case of specialised routines, options may be chosen. Then the action buttons at the bottom of the interface perform the calculations. Red or Green traffic lights indicate invalid/valid entries, and text windows provide status and other reports (more detailed diagnostics may be found in some cases on the console window from which QSAS was launched).

Arithmetic and plug-ins provide a Help menu which displays the information on the routine as described in the *.qtpl template file. These can include a description of the algorithm and any conditions on the inputs, options, or outputs.

Joining Time Series

Analysis of time-ordered datasets often requires data to be placed onto a common set of time tags prior to further analysis. For example, taking the difference between two time series of plasma density, e.g. n1(ti) and n2(tj) requires that each time ti at which n1 has a value has a matching tj so that n1(ti) - n2(ti) can be found. Since often n1 and n2 come from different sources, this is not usually th

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## Tips/FAQ

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Bugs

Page created by Steve Schwartz, csc-support-dl@imperial.ac.uk
Last up-dated: July 2000