@Anthrazit To replace an existing Maple Cloud document, you need to ensure that the Document Properties used by Maple Cloud match those of the original; without that there won't be a "Publish Update" button in the dialog that appears after sending the book to the cloud. Open the Maple book and inspect the Document Properties (File > Document Properties).  The important ones are those that start with "X-Cloud" and "application_type", "authors", "description", "language", and "title", however, you should be able to ignore the X-CloudVersion, since that is incremented by the cloud site.  The others must match the original (possibly some could be changed, but its probably safer to change them at the site).

I generate Maple books from a Makefile so don't actually have experience in manually changing these properties, but it should work.

Followup When you first upload a Maple worksheet/book to the cloud, be sure to save the file after doing so.  The process of uploading it adds the fore-mentioned Document Properties.  If you didn't save it, they won't exist when you go to update.  In that case, you should start by downloading the file. 

I haven't noticed that. I've had issues updating packages, but that's a separate issue and caused by me making changes that prevent Maple from identifying the book as an update. What do you observe after you click the "Upload to Cloud" selection?

@AmusingYeti Note that kernelopts(platform) returns "unix" for both linux and Mac OS X.  If you need to distinguish them, consider kernelopts(system).

I uploaded a Maple package, UTF8, that uses native methods for similar functionality, onto the Maple Cloud a few years ago.  

@Jaqr It seems unlikely, then, that limited disk space is the issue. 

That is possible. On linux, Maple normally uses the /tmp directory.  How much do disk space do you have there?  Use, say,

df -h /tmp

@acer The example in the LibraryTools:-Save help page is frightening; if executed it would save directly into the main maple mla.

What's the application?  That is, given a Maple worksheet, do you want determine what comboboxes are in it?

I have a command-line tool, written in Maple using the Bark package available on the Maple cloud, that I use from the linux command line to inspect and modify worksheets.  For example, here I use it to determine what comboboxes exist in a given worksheet:
 

$ ect Linearization.mw --type=ComboBox
cmbInputVarRoot
cmbOutputVarRoot
cmbInputVar
cmbInputSignal
cmbOutputVar

If interested I could push it to the cloud (might take a while to get it ready).

@jfk_dora You can also use subs[eval]( X = Y, Z).  That performs the substitution, then evaluates.

@nm Given a list, say L := [a,b,c], L[] is equivalent to op(L), both of which return the expression sequence (a,b,c).  This also works with sets. In the usage sort(...)[], the list returned by sort is converted to an expression sequence, then passed to the inert addition operator.  Inert addition is used (rather than regular addition) so that the terms don't get automatically permuted to the original order.

Alas, currently there isn't a good way to do this.  I don't recall the precise reason that the noise blocks do not yet work in MapleSim. They use external code that currently is not supported.  Will look into it.

I've done so with fmpy but not with pyfmi (haven't used it), but assume it can be done.  As Thomas Richard suggests, make L a tunable parameter (in the fmu generation).  Will look into using pyfmi when I get a chance.

@Carl Love Thanks.  So far as replacing abs(n,x) with x, I'm embarassed to say I didn't bother to consider whether it made any sense. Also, the _@@0 took me a minute to comprehend. I've frequently lamented the lack of a builtin identity; that isn't it, but it is ingenious.  Note that 0@@0 also works.

@Carl Love That doesn't seem right.  I don't have &inside so didn't actually test, but doesn't the replacement for a multiargument abs have to return only the last argument?  So rather than the eval, abs=_@@0, I'd use x -> op(-1,x).

I assume you mean a template something like the Custom Component template, which works for continuous models. It could be extended to handle discrete models.  Do you have an example of discrete equations you want to model?