Frequently Asked Questions

    How do I submit a Matlab job to the batch cluster?

    In order to run a matlab job on the RCE Batch Cluster, you must set some environment variables and run matlab in command line mode. HMDC has developed a simple program to automate this process called submitMatlabBatch.sh.

    To run your Matlab code as a batch job, open a terminal window in the RCE and type:

    submitMatlabBatch.sh myfile.m

    Use the name of your matlab code file in place of myfile.m, and your code will run one single iteration as a batch job.

    Standard output from your job will be...

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    How do I use files in my home directory from my batch job?

    When you submit a batch job, the R script is copied to a staging area and then executed by a cluster node. This means that you must set paths explicitly in your R scripts. To set paths, add the following code to the beginning of all your R scripts. This tells R to find the absolute path to your home directory, then set the working directory to that path:

    setwd(path.expand("~<username>"))

    Use this code to address such problems as the following:

    Loading required package: MASS Error in file(file, "r") : unable to open connection In addition:...
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    How can I make my batch submission track iteration number?

    Condor refers to the iteration number of your batch job as the "Process" number, and the descriptor for your job in aggregate as its "Cluster" number. A Job ID consists of both, separated by a dot: $(Cluster).$(Process)

    To track iteration number for batch submissions, use one of the following methods:

    • Pass the iteration number as an argument to the executable. For instance, for an R job:
      • Add --args '$(Process)' to the Arguments line of your Condor submit file. This passes to the R interpreter the process number of the R run, which progresses...
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    Can I run multi-threaded jobs?

    If you would like to use multiple CPU cores simultaneously, please be sure to reserve the appropriate number of CPU cores when submitting a job. This will ensure that your jobs do not compete with other jobs for a CPU, and are allocated resources for your exclusive use.

    Many applications and programming libraries can make use of multiple CPU cores simultaneously by running multiple active threads or processes.

    Jobs in the RCE are guaranteed access to as many CPU cores as are reserved for the job. More CPU cores may be available, but if there is competition for CPU cores...

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    How do I check RCE disk quota?

    What is Quota?

    Your "quota" is a limit on your data storage space.

    Types of Quotas

    • User Quotas: Each RCE user has a separate home directory quota of 2GB. Please note that when you move files to your Trash, they still count against your home directory disk quota until you empty your Trash, regardless of where they were moved from.
    • Group Quotas: Each research project in the RCE is designated a "group" and each group is given a "project space" with a separate quota. You may also have a...
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    I'm unable to log in -- what can I do?

    There are several troubleshooting steps to take if you cannot log in to the RCE desktop:

    1. Verify that your credentials are correct by logging into the HMDC Account Self Service page. If you cannot log in, then the problem lies with your RCE credentials, and you will not be able to progress any further.  Please reset your password by visiting the Account Self Service page and clicking the "Forgot your password?" link,...
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    Copy/Paste to the RCE desktop isn't working!

    When you copy and paste text between environments, you use the clipboard function.

    If you have problems copying and pasting between environments, please try using ApplicationsRCE UtilitiesRestart Clipboard Sync.

    How do I share files with my collaborators?

    Set up a project space

    The simplest way to share files with collaborators in the RCE is to use a project space, which is a folder you all have access to. Send us a support request asking for a shared project space and we will create one for you. (Storage sizes over a certain amount are subject to a nominal fee.) Be sure to include the names of your collaborators.

    Once you have a project space it will be linked from your RCE home directory under ~/...

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    How do I stop windows from jumping to the foreground?

    The default window behavior in the RCE uses the focus-follows-mouse model, in which the user selects windows by merely pointing at them, and the selected window jumps to the foreground.  To change this behavior go to:

    Applications → RCE Utilities → Change Windows Focus Behavior

    The focus policy change is immediate.

    How do I copy/paste from a RCE terminal?

    If you are running a RCE desktop session from a Windows client, you are probably used to using ctrl+c for copying and ctrl+v for pasting. Terminals remap these functions to shift+ctrl+c and shift+ctrl+v, respectively. The ctrl key is used for specific operations, such as terminating command-line operations (ctrl+c). You can also right-click in the terminal to copy and paste.

    Who can participate?

    Anyone above the age of 18 may participate in the experiments at the Harvard Digital Lab at Harvard University.

    Will any of my personal information be collected?

    No personal information will be collected at any point of participation at the Harvard Digital Lab.

    You may be asked questions about yourself, to help us understand more about you, such as "What is the highest level of education you have completed?". You do not have to answer these questions if you do not feel comfortable. These questions are completely voluntary, and do not affect your overall participation in the research.

    What is the purpose of the research at the Harvard Digital Lab?

    All the original experiments and surveys at the Harvard Digital Lab are designed for academic research, dedicated to answering questions about how we interact, consume information, and make decisions. With your participation, the results will provide insights into key complex social relationships. Our researchers may publish the results in a scientific journal, post as a blog on an academic site, or featured in a chapter of an original academic text.

    As you take each study, the researchers will give you more specific information on the what, why, how and time commitment in the...

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    How often can I participate?

    You can participate in as many individual experiments as you'd like.  However, we ask that you do not participate in the same experiment more than once.

    What happens to my responses?

    Your responses are stored anonymously and securely by the Harvard researchers leading the study. Your answers will only be used for the purposes of academic research and will always remain anonymous.

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