The JAVA Interface


The new interface to the NON-SMOKER results offers the same features as the previously used interface which used a simple HTML form. Additionally, it offers plots of the downloaded cross sections and reaction rates. It is even possible to compare multiple plots on one screen. This added functionality makes it superior over the previous HTML interface. Only users who cannot or do not want to run Java applets on their computers should resort to continue using the old version.

System Requirements and Restrictions

The new interface is a code written in Java 1.1 and running as an applet on your machine. The size of the applet is optimized so that it can also be used on screens with a moderate resolution. This results in the following system requirements: Since the applet is run as "untrusted code" the controlling browser sets some strict limits on what the code is allowed to do. It CANNOT read or write files or other information from your disks. It is only allowed to established an internet link to the machine where it was downloaded from. Thus, the user does not have to worry about security.
On the other hand, these security issues also lead to restrictions in the performance of the applet:

How to Use the Applet


When downloading the web page, the browser will download the compiled code and start it in the predefined applet window. The applet size is initially set to 640x480 but the applet tries to expand if a screen with higher resolution is used and the browser permits it (see the security restrictions above). For each plot request the code will establish a HTTP connection to download the data. The conversion of the data to plots is done offline in real time.

The applet interface appears within a HTML page displayed by your browser. It is subdivided into three regions:

  1. The text region on top
  2. The plot viewport in the center
  3. The control section at the bottom
The text region displays the data and messages resulting from your queries. The scroll bar on the right side can be used to view earlier messages. The plots are shown in the viewport. The scroll bars on the right and the bottom can be used to view other portions of a plot. While the size of the other regions remain roughly the same regardless of screen resolution, the viewable area in the viewport will become larger when using a screen with higher resolution. On low resolution screens the use of a separate plot window (see below) is recommended. Finally, the control region contains all components to make queries and control the appearance of the plots. After entering the required information into the text fields a query and plotting can be initiated by clicking on the Plot button. All entered information will be deleted by using the Reset button. The Clear button only erases the plot and the text region, leaving the entered information for further use.

Listing of Cross Sections and Reaction Rates

Listing and plotting of data works simultaneously. Enter the required information (user name, password, element symbol, mass number), select Cross Sections or Reaction Rates, the type of the reaction and the mass formula which should be used in the calculation of the resulting values. (The required input is the same as when using the old HTML form; please refer to the old documentation for further information.) Then press the Plot button and the request will be sent to the server which will return the relevant data.

The result of the query is shown in the text region in a similar format as was previously returned by the HTML form. However, some of the alignments may be slightly different because the formatting commands returned with the data are ignored. It should be noted that always three reaction channels are returned in the listing, even though only one reaction was selected. These are all possible channels with the same entrance channel. The results can be read and understood in the same way as in the old HTML form. See the old documentation for further information.

Plotting of Cross Sections and Reaction Rates

At the same time when a data listing is successfully returned and shown, a plot of the selected reaction (and only this reaction channel!) is generated. The plot can then be examined in the viewport section by using the scroll bars. If the checkbox at Separate plot window is selected, an additional plot window of the size 800x600 pixels will pop up and also display the plot (see Requirements and Restrictions above for possible restrictions of use).

The buttons Clear and Reset can be used to clear the plot and data areas or the plot, data and input fields, respectively.

The scale and axis are chosen automatically so that the curve will fit into the plot area. Plots of cross sections are always doubly logarithmic plots, displaying log10(cross section) on the y-axis and log10(energy) in the x-direction. Plots of reaction rates are singly logarithmic plots, displaying log10(reaction rate) on the y-axis and the temperature (in 109 K) on the horizontal axis.
Only major tick marks are labeled. If on one axis (this usually only happens on the vertical axis) only one labeled major tick mark is shown (which gives the order of magnitude), then and only then unlabeled minor tick marks (referring to "times 2", "times 3", "times 4", etc.) are drawn. Minor tick marks are shorter than major tick marks and minor tick marks are always unlabeled, contrary to major tick marks.
Cross sections and reaction rates below a certain threshold value may be shown in the listing but are not plotted. Currently the limit is set to 1.e-30 for both cross sections and reaction rates.

Single and Multiple Plots

It is possible to overlay several plots of the same type (i.e. cross sections or reaction rates). If the checkbox at Cumulate plots is NOT selected, the plot area will be erased before each new plot. To enable overlays, select Cumulate plots (it is selected by default). Subsequent plots will be drawn with a different color in the same coordinate system as the first plot. After 10 colors the color cycle will repeat itself.

Note that the first plot in a series of overlay plots determines the scale of the x- and y-axis. Subsequent plots will not change that scale. If you do not find your second, third, ... curve it may be off scale! Choose the plotting sequence well.

Using the Clear button erases the plot area and the text area and will start a new series of overlay plots. The same happens when the type selection switches from Cross Sections to Reaction Rates or vice versa. It is possible, however, to overlay plots with different reactions (e.g. (n,g) and (p,a), if that makes any sense).

The title of the optional additional plot window will always display the last plotted reaction. The color legend can be retraced by scrolling back in the text field.
If you want print outs of your plots, use the separate plot window and some "print screen" tool.

Important note: If no additional plot window was used in a series of plots and if the additional window is activated in the midst of a series of overlay plots, then the axis of the new plot window will not use the same scale as the axis in the regular plot area. This may make it impossible to see the plots and all subsequent overlayed plots in the same way in both the regular plot area and the additional plot window. If you want an additional plot window, activate it BEFORE starting a series of plots. If you activate it later, you have to use the Clear button and redo the series of plots.

Description of Applet Components

Error Messages

The error messages returned by the server are the same as for the old HTML form. If an error is returned no plot is made. A list of error messages can be found in the old documentation.

Do not use a proxy server when connecting. Otherwise you might continue to receive the same error messages or old data even when the error has been fixed in the meantime.

© Dr. Thomas Rauscher (email), last change 2006-Aug-20