Memory Issues

PaleoMag is initially set up for a bare minimal number of samples and fits. This will almost certainly be too small for most users. The user should adjust these numbers through the "Extras..." item in the Edit menu when first launching a new copy of the program. Note that changing the order of demag steps increases Demags/Locality without increasing Demags/Sample. Although changing these values takes effect immediately, some arrays are defined when the program is first started and are not redimensioned at any later time in the code, so it is generally a good idea to change the maximum values in the Extras... dialog box and then restart the program. Changes to the memory limits are stored in the resource fork of the program and are not reset each time the code is rebooted. (Somewhere down the line, this will all be changed to use a Preferences file...)

This program does not handle memory elegantly; if you exceed available memory or exceed an array bound, the code crashes. Because there is no file in memory, no data should be lost when this happens. (Maybe in the future this will become a little less fatal). If you run out of memory (error 7) and you are using MultiFinder or System 7.x, then increase the size partition by opening the Info window of PaleoMag and increasing the size in the box in the lower right part of the window. If you exceed an array limit (error 9) then consider your dataset and increase the appropriate values as described above. In some cases a copy of PaleoMag might have been set with values too large for it to be started on some Macs (this is why I usually distribute it with low values); if this has happened, you will either have to start PaleoMag on a machine with enough memory, or you can directly edit the array limits using ResEdit. The array limits are stored as numbers in string ("STR ") resources with ids of 200 (maximum number of samples/locality), 201 (maximum number of demags in any sample), 202 (maximum number of least squares directions/locality), and 203 (maximum number of demag steps/locality).

Presently many of the arrays in the code are dimensioned dynamically; this means that you might be able to run the code with a large number of samples without exceeding memory as long as you keep the number of windows open at once to a minimum. The most memory intensive windows are the two "Locality" windows ("Locality Equal Area..." and "Locality Strat Plot...") closely followed by the two "Least Squares" windows. Again, if the program crashes under MultiFinder/System 7.x and you need the multiple windows, increase the size partition in the GetInfo window for PaleoMag.

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