Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

This website has been deprecated and exists as an archive only.

The TORTOISE website has been moved to https://tortoise.nibib.nih.gov.

For any information about TORTOISE generation V3.x.x, please refer to the new website.

1.3.3 Running DIFF_CALC

We highly recommend the use of the IDL VM as it is platform independent, and should therefore encounter fewer problems than running with an IDL license.

Linux and Max OS X can either run the IDL VM from command line or from the IDL VM file selection menu.

With precompiled IDL Virtual Machine (VM)

  • navigate to the install directory/DIFF_CALC/diffcalc_main
  • type calcvm
    Note: If you are running the software on mac, please type ./calcvm at the terminal. This will ensure you are running the software from your home directory, where all the settings file to run the software are stored.
  • Click anywhere in the IDL VM window to dismiss the splash screen and display the file selection menu

With IDL Virtual Machine (VM)

Note: we recommend using the above option with the precompiled IDL VM due to some errors reported by users. If you run into any errors using the following run commands, please try the precompiled option.

Command Line Linux:

Enter the following command in a shell: idl -vm=<path><filename>.sav. For example:

idl -vm=/home/TORTOISE/DIFF_CALC/diffcalc_main/diffcalc.sav

Note that if you first navigate to the diffcalc_main directory, it is necessary only to type:

idl -vm=diffcalc.sav

Click anywhere in the IDL VM window to dismiss the splash screen and display the file selection menu.

Command Line Mac:

Enter the following command in a shell: idl -vm=<path><filename>.sav. For example:

idl -vm -32=/home/TORTOISE/DIFF_CALC/diffcalc_main/diffcalc.sav

Note that if you first navigate to the diffcalc_main directory, it is necessary only to type:

idl -vm -32=diffcalc.sav

Click anywhere in the IDL VM window to dismiss the splash screen and display the file selection menu.

File Selection Menu:

Enter the following command in a shell:

idl -vm {-32 if using Mac}

The IDL VM window is displayed

Click anywhere in the IDL VM window to dismiss the splash screen and display the file selection menu.

Locate and select the .sav file, and click Open

With Full IDL license (Linux or Mac OS X)

Go to the diffcalc_main directory inside the DIFF_CALC install directory in a shell

Type "idl" in the command prompt.

On the IDL command prompt type: IDL> diffcalc