MaplePrimes - answers and comments on Question, Lost kernel connection

Corrupt worksheet

Robert Israel — Mon, 25 Jan 2010 10:36:40 Z

You might try removing the output from the worksheet (under Edit on the menu bar, Remove Output, From Worksheet) before trying to save. This should be less likely to produce a corrupt worksheet.

Under normal circumstances, that warning message occurs when you save a worksheet in .mws format from the Standard GUI. Are you sure you're using Classic?

Ahh, classic vs standard confusion

longrob — Mon, 25 Jan 2010 10:57:23 Z

Thanks for helping!! Hmm, it seems I'm using standard gui, with the option for default format for new worksheet set to worksheet not document. We have to submit mws files to our tutor for assignments and we were advised to use classic mode. I originally had maple 11 supplied as part of my course, and it had an option "classic worksheet maple 11" in the menu, but I had some problems with it (64 bit issues) and since upgrading to maple 13 I don't have a "classic worksheet maple 13" option in the menu, just "command line maple 13" and "maple 13"..contrary to what is says here: http://www.maplesoft.com/support/help/AddOns/view.aspx?path=versions Removing the output doesn't seem to affect the "lost kernel connection" problem. Thanks again.

unassigned variable

longrob — Mon, 25 Jan 2010 14:30:11 Z

OK, so I found that the cause of the problem of Maple "losing the connection to the kernel" was that a variable in my ODE system was unassigned. Strange, and not convenient !

is this normal ?

longrob — Mon, 25 Jan 2010 15:04:46 Z

restart; ross_x:=diff(x(t),t)=-y(t)-z(t): ross_y:=diff(y(t),t)=x(t)+a*y(t): ross_z:=diff(z(t),t)=b+x(t)*z(t)-c*z(t): rossler_sys:=ross_x,ross_y,ross_z: DEtools[DEplot3d]({rossler_sys},{x(t),y(t),z(t)},t=50..200,[[x(0)=1,y(0)=1,z(0)=1]],scene=[x(t),y(t),z(t)],stepsize=0.05,thickness=1,linecolor=blue,orientation=[40,120]); I have created a worksheet with just the above commands (mw and mws) On my system it results in a lost kernel connection, and then a corrupt worksheet using both mw and mws worksheets. I know that the cause of the problem is that a, b and c are not assigned values when DEplot3d is called, but it doesn't seem right that this then causes Maple to lose it's kernel connection and corrupts the worksheet if I attempt to save it. :(

Classic

Robert Israel — Mon, 25 Jan 2010 20:57:33 Z

There is no Classic in the 64-bit version of Maple. It ought to be possible to use a 32-bit version of Maple in a 64-bit operating system, but problems have been reported with that too (see e.g. www.mapleprimes.com/forum/wheresclassic).

Bug?

Robert Israel — Mon, 25 Jan 2010 20:50:22 Z

That is a bug in the Standard GUI. I hope you'll submit an SCR. The problem, it seems, is that you get a CURVES plot structure with all its points [undefined, undefined, undefined]. But this should not crash the GUI. Classic just produces

Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters)

Warning, plot may be incomplete, the following errors(s) were issued:
parameter 'a' must be assigned a numeric value before obtaining a solution
Plotting error, VIEW must contain numeric ranges