The QC1 database

This document describes the design of the web interface to the QC1 database which enables interactive plotting of QC1 parameters.

Because of the large number of existing parameters, it seems generally not useful to offer a tool which can do anything. Therefore this interface is thought for the expert user who wants a 'quick and dirty' tool for interactive plotting of selected QC1 parameters.

2. Aim

The present strategy is to offer the following functionalities:

• a single X-Y plot of one selected QC1 parameter versus another,
• from a selectable range in time,
• filtered by the relevant instrument parameters,
• with simple statistics options like mean, linear regression, errors,
• for the two formats gif (web view) and postscript (high-quality output).

3. Format of interface

The interface is an HTML page with a predefined format. It has:

• three fields (tables) for definition of X axis parameter, Y axis parameter, and filter parameters
• one field (table) for statistics and format options.

This interface is created from scratch by a script which reads from the format description table (e.g. uves_bias) the relevant information into a template page.

4. Configuration columns

The format description table needs three configuration columns:

• plot_flag
• sort_flag
• keyword_ype

plot_flag describes if and in which way a key is relevant for plotting. There are 4 options:

• XY - plottable on X and Y axis (there may be multiple keys with XY)
• XD - default choice for X axis (one and only one key permitted)
• YD - default choice for Y axis (one and only one key permitted)
• F - offered as filter (multiple keys permitted)

sort_flag is an integer number which is used for user-controlled sorting of multiple options. Multiple values are permitted:

xdy - default choice for x; plotting on y axis also possible
xyd - default choice for y; plotting on x axis also possible
fxy - offered as filter, but also plottable on x and y

keyword_type has one of three values (gen/qc1/ins) and is used for the qc1_browser interface.

5. Interface design

The interface is called qc1_plot. It is a form which consists of 4 tables: X axis, Y axis, filter, options.

The value of plot_flag, together with a set of rules and the sorting flag, describes the way the query interface is constructed.

1. X axis: radio button with default value denoted by XD, shown on top. Other choices (those keys with plot_flag = X or XY) are offered below the default value, sorted by sort_flag. All choices are shown in a table, with columns: radio button, field_name, field_description.

2. Y axis: radio button with default value denoted by YD, shown on top. Other choices (those keys with plot_flag = Y or XY) are offered below the default value, sorted by sort_flag. All choices are shown in a table, with columns: radio button, field_name, field_description.

3. Filter: a set of select boxes (sorted by sort_flag), one for each key with plot_flag = F. All choices are shown in a table, with columns: field_name, select box, field_description. The select box should offer all possible entries ('select distinct...') plus 'any'. The initially selected value should be the first available non-any.

4. Options:
Range in time: select boxes; f"from" and "to"; default values should be: "from" = today minus one month, "to" = today. Format is YYYY-MM-DD.
Statistics options: radio buttons; one set for average, one set for errors. "average" has: none (default), regression, mean. Options are mutually exclusive. "errors" has: none (default), 3 sigma, +/- 10% (mutually exclusive).
Format options: radio buttons; gif (default) and ps .

5. Launching:
buttons for "submit" and "reset".

6. Plot format

This is the description of the interface only. The plot engine needs to be determined independently. The interface delivers to the plot engine:

• the parameters to be plotted on the X and Y axis, respectively;
• filters to select for instrument parameters and time range;
• options for statistical analysis (regression line, mean, errors);
• the plot format.

This should be sufficient for a unique description of the plot desired. The plot engine then should create a plot as specified, with the additional rules:

• X scaling: X_min and X_max to be taken from minima and maxima of selected X sample, modified by +/-10%;
• Y scaling: Y_min and Y_max to be taken from minima and maxima of selected Y sample, modified by +/-10%;
• tickmarks: hopefully automatically determined by plot routine, otherwise t.b.d.
• axis labels: selected field_name
• plot label: table_name, Y field_name vs. X field_name, filtered names and content
• if selected: mean value, error value plotted as label somewhere (t.b.d.)

7. Example page: uves_bias_plot.html

The example page uves_bias_plot.html illustrates the concept and the design. It can be used as template.

8. Example format description table

The set of format description tables for uves is found here (.xls).

9. Status of interface

Send comments to <Reinhard.Hanuschik@eso.org>
Last update: Oct 17, 2002