6.302 WebLab:
Frequently Asked Questions
- 1 Problems Loading Lab Client:
- 2 Problems Exporting Data:
- Q2.1: When I right-click on the graphs, the menu comes up but all options except "Delete all graphs" are disabled and cannot be selected.
- Q2.2: When I export the ".m" file and then try to open it in Matlab, although the name appears in the directory I saved it in, Matlab says the file doesn't exist.
1 Problems Loading Lab Client:
Q1.1: After hitting the Launch Client button, the page refreshes but nothing seems to happen and no applet gets loaded.
Before launching the Lab Client applet, please make sure you have the latest Java Plugin installed on your system and have enabled applets to run on your browser. You can download the newest Java Plugin here.
Q1.2: The Lab Client applet loads, but I get an error that says: "Server error: Failed to retrieve lab configuration."
When logging into iLab, make sure to do so only through the following URL: http://ilab.mit.edu. Accessing the WebLab through any other URL (including http://ilab) will not work.
If this solution does not solve your problem, it is possible that your session may have expired (idle sessions last approximately 30 minutes). In this case, try logging out of iLab and logging back in again. Then try launching the Lab Client one more time.
2 Problems Exporting Data:
Q2.1: When I right-click on the graphs, the menu comes up but all options except "Delete all graphs" are disabled and cannot be selected.
When selecting individual graphs to export, please make sure to right-click on top of the actual graph line that you wish to export. For example, if you would like to export the data for the blue graph, then you must right-click over some portion of the blue line that represents the blue graph. Clicking on any other portion of the graphing area will not allow you to export the graph.
Q2.2: When I export the ".m" file and then try to open it in Matlab, although the name appears in the directory I saved it in, Matlab says the file doesn't exist.
When loading a ".m" file in Matlab, do not select the Open option from the File menu. Instead, update the current directory in your Matlab prompt to the directory where your ".m" file is stored. You can do this by using the cd command, or through the Current Directory input field if running the desktop GUI window. Once in the correct directory, you can type in the name of your ".m" file without the trailing ".m". (e.g. type in graph if your results are stored in graph.m.) After hitting return, your experimental values should be available to you via the ilabdata variable.
Incidentally, in some versions of Matlab the name of your ".m" file may not start with numeric characters for the above to work (e.g. saving your file to 6302results.m will mysteriously fail).