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Mathcad 15 does not update when variable values change

Joeboy
12-Amethyst

Mathcad 15 does not update when variable values change

I am using Mathcad 15. I routinely create rather long documents where all variables are given names so I can change a variable value in one place rather than searching for every occurrence - pretty common. I find that 15 often does not update results when I change a variable value, even after goin to "recompute file". The only way to get it to update is to save and reopen the file. This is particularly true if the result that should change is an "inserted math region". Has this been reported ?

16 REPLIES 16
RichardJ
19-Tanzanite
(To:Joeboy)

Which version of 15 are you running?

Joeboy
12-Amethyst
(To:RichardJ)

Mathcad 15 (M010 [])

RichardJ
19-Tanzanite
(To:Joeboy)

Same version as me. I do ocasionally see update problems, but nothing as severe as you report. Ctrl F9 always fixes it for me.

StuartBruff
23-Emerald II
(To:Joeboy)

I've noticed that for quite some time. Occasionally, I'll make a change somewhere else in a document and the non-updating regions will also update.

Stuart

RichardJ
19-Tanzanite
(To:StuartBruff)

Sometimes I get a region that not only does not update, it does not even display an answer. I find that moving it down the page and then back up fixes it.

I experience the same problem, which especially appears when storage use is growing towards 1GB. It does not depend upon the resources of the computer (and I have a big one ). What I never do is use definition of variables with immediate output of the value in the definition formula. Their update behaviour is much worse, so the functionality is essentially crap.

thanks for this tip! i always type = right on the formula and i notice that the pc are slower after while..

i have some problems with references files too, sometimes i need to make the reference again to update the new file, this is quite annoying..

the mathcad have some file output like the .m files of matlab?

RichardJ
19-Tanzanite
(To:ptc-3952492)

To update a reference, select it and hit F9 (using Ctrl F9 for the whole worksheet does not update it).

A .m file is a matlab script, so surely that's just the equivalent of a Mathcad worksheet?

sorry Richard, i mean the .mat file, not .m file.

thank you for the F9 tip!

RichardJ
19-Tanzanite
(To:ptc-3952492)

There is no specific binary file format, but there are READBIN and WRITEBIN functions. The .mat file format looks fairly simple (see http://www.mathworks.com/help/pdf_doc/matlab/matfile_format.pdf), so it would not be that hard to write functions based on READBIN and WRITEBIN that would read or write such files.

yes Richard, i already do that, but the result data are "raw" after that.. at least in matlab, the name and type of variable are available when we import the .mat file.

so my issue is if the mathcad have some specific file to storage variable object, but not in a worksheet. That file carries the variable properties like name, unit, type of data, etc..

maybe some xml file like:

<var>
<name>Varname</name>

<type>float</type>
<unit>m²</unit>

<value>232</value>
</var>

i have to do some specific reader/writer component to do that?

RichardJ
19-Tanzanite
(To:ptc-3952492)

Unfortunately, there isn't any such file read/write. I agree that it would be very useful sometimes if there were.

Writing such a file would actually be possible. The data values are of course easily available. In Mathcad everything is stored as a double precision float, so we don't need a variable type, except to define which numbers belong to a particular array. That would be easy enough. Quantities with units are always stored internally in SI. Getting the units is a bit more tricky, but possible. A scripted component could be used to get the region XML via the automation interface (I have such a component already, in fact), and that contains the unit information.

Reading the data back, and creating an appropriate variable, is also possible. Assigning values to a variable is easy, but there is no easy way to assign units (this was easy in version 11, and will be easy in Prime, but in versions 12 through 15 it is not). It can be done by modifying the XML of a region that already exists though, again via a scripted component (and again, I already have such a component).

It would be a lot of work though, and it would require the use of scripted components to handle the unit information. It would be much better if PTC provided such functions (Hi Jakov, are you reading this? ).

this feature will be veery useful to control version and progression report in a project development, for MDO purpose and collaborative environment too.. but thanks for this discussion and tips, i really appreciate that!

i always type = right on the formula

The most typical times I see this behavior are when I've displayed results inline. The internal calculation of the variable is correct but the displayed answer might be incorrect. I agree it is very annoying. I always have to print my final deliverables after opening the sheet "fresh"; making any changes might result in an incorrectly-displayed result in my submission to the client!

RichardJ
19-Tanzanite
(To:ptc-1176891)

I thought this bug (i.e. inline evaluatoins not updating correctly) had ben fixed. It's certainly been reported. I rarely use this feature though (it's less useful tome than backward compatibility of the worksheet), so I'm not sure of that.

This needs to be submitted to the support team. I have problems, but CTRL-F9 fixes.

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