I am trying to put a number of related 2-d plots into a 3-d frame so I can see them stacked up in the third dimension (which follows a parameter) and rotate things around.

The way I once did this successfully was to create the 2-d plots and then use plottools:-transform to move the individual plots in the third dimension, like so:

plt:=plot(something);

tr:=plottools:-transform((x,y) -> [x,2,y]); # the "2" gets changed for the other plots (not shown here).

plots:-display(tr(plt));

The only effect I can get is that the GUI gets confused and I have to close and reload the sheet to get it back again. I have a (complicated) sheet where this actually works, but I am not able to make it work even in the small example I am posting below.

Any hint of where I am going off trail is appreciated. Incidentally, this problem is what led to the corrupted sheet I had maybe a week ago.

Thanks,

Mac Dude.

display3d.mw

I got bit by Maple when I tried to combine a number of 2-d plots into one 3-d plot, using plottools:-transform to space the plots out in the third dimentsion. I have done such things before. This time, the first time I executed the final plot statement the GUI got clobbered and somehow also the whole worksheet (I may have saved it). Now, when I load it nothing shows up and worse, I cannot enter anything in the worksheet, it is completely screwy. I looked at the XML code in Emacs and it validates and I cannot find anything obviously wrong with it, i.e. no dangling tags or similar.

I used Maple 2017. In Maple 2015 the same worksheet overprints itself & makes a big mess on the screen. It is similarly unuseable.

Can one of the experts have a look at this? Although rare I have experienced similar issues on occasion before & would like to know how to get this into a sane state.

TIA,

Mac Dude

triangle_analysis.mw

In ScientificConstants, the density of carbon is given as 2.2 g/cm^3. That happens to be the value for graphite. Carbon comes in different states with different density, diamond being one of them, amorphous being another. Is this somewhere in ScientificConstants where just I cannot find it, or is it not there?

TIA,

M.D.

PS: I do know the values and where to find them (Particle Data Group). I'd like to use ScientificConstants so I can write a more general piece of code.

I am trying to add a specific property (radiation length) to the Elements in ScientificConstants.

To do this  I first 

ScientificConstants:-AddProperty(radiationlength); # this seems to work

I then load a table of element name - radiationLength pairs (it is really a bigger table but only these are of interest):

data:=ImportMatrix(cat(libname[1],"/RadiationLengthTable.txt"),source=delimited,\
                       datatype=anything,delimiter="\t"); # works too

(I made the file using downloaded data).

I then want to fill the radiationlength properties for all elements for which I've got the value:

for i from 1 to LinearAlgebra:-RowDimension(data) do
  elemt:=data[i,1]; # the element name as a string
  ScientificConstants:-ModifyElement(cat(elemt),radiationlength=[value=data[i,4],units=g/cm^2]);
end do;

which fails with the error

Error, (in ScientificConstants:-ModifyElement) element ``H `` is not known

H is the first element in the table of radiation lengths so it is getting the right one.

At  issue is that somehow the element name (called descriptor in the Help files) does not seem to get properly evaluated. In fact I tried various ways "by hand", none except just the unevaluated element name (i.e H,He etc. worked).

There must be a way to set these in a loop. Does someone know how?

TIA,

Mac Dude

I have a code that is built on a module which in turn contains records, procs etc. to model certain electronic devices.

The main program first instantiates the various circuits I am using. These are mostly Maple records. It then enters a loop that iterates over a number of cycles this system executes in order to build up statistics.

My problem is that somewhere the code has a memory leak, and Maple eats up rather vast amounts of memory, that increase with the number of cycles in the loop. I suspect that some of the methods I am calling allocate a new instance on each cycle, which is not the intended behaviour. What I am looking for is a way to diagnose e.g. which record, or which proc, gets allocated anew every time. I know about usage but that prints out only the amount of memory allocated; that does not help; I know the number is large. I am looking for a tool that e.g. tells me that record xx is allocated 1000 times etc.

Thanks,

M.D.