Bug in Mathcad 15 when changing a vector element from text to scalar

[Werner_E]

I came across a strange effect while reading in some data from an Excel sheet and changing some elements which where formatted as text in Mathcad back to be numbers. Mathcad woul not recognize the resulting matrix/vector to be a matrix of scalars (while it is, or at least should be).

See below and attached a simplified example. Can anybody explain that strange effects?

BTW, the same sheet converted works fine in Prime2.

Addendum: If you make the second assignment work as described by pressing F9 and you move arround the first V^2 assignment, it works, too!!????

The German error message is something like: "The object reference is not set to an instance of an object". Obviously users are not expected to ever see this message.

(Remark: The absolute value has to be set from Determinant to absolute value)

[RichardJ]

Obviously a bug. I'm surprised it hasn't been noticed before.

[Werner_E]

Richard Jackson wrote:

Obviously a bug. I'm surprised it hasn't been noticed before.

Yes, indeed. Not sure if this bug was present in older Mathcad versions. I am using MC15 M020.

I just reported it to PTC (case # 11508302, but I'm not sure if others are allowed to look at it)

[RichardJ]

Not sure if this bug was present in older Mathcad versions

Not in MC13. I don't have an easy way to test MC14 or earlier builds of MC15.

[VladimirN]

Werner Exinger wrote:

...I just reported it to PTC (case # 11508302, but I'm not sure if others are allowed to look at it)...

That's right:

I'm having the same error in MC15 M020. But in version MP 2.0 all works fine:

[Werner_E]

VladimirN. wrote:

I'm having the same error in MC15 M020. But in version MP 2.0 all works fine:

Yes, thats the Mathcad version I use, too. Already stated that in Prime2 all is OK as it should.

[MihaiMoraru]

Werner Exinger wrote:

Addendum: If you make the second assignment work as described by pressing F9 and you move arround the first V^2 assignment, it works, too!!????

The second assignment works also when I assign the stack(...) to V1 and then delete the "1". And as you say V^2 works too.

It is so strange to make changes bottom-right with an effect on the upper-left of the worksheet!

Werner Exinger wrote:

The German error message is something like: "The object reference is not set to an instance of an object". Obviously users are not expected to ever see this message.

The error message is in English in my worksheet. Can it be from Windows?

[Werner_E]

It is so strange to make changes bottom-right with an effect on the upper-left of the worksheet!

Yes, its sure a bad programming error throwing that NullReferenceException. Obviously the changes at the bottom happen to create an object properly and so the upper parts are affected, too.

The error message is in English in my worksheet. Can it be from Windows?

I use a German version of Mathcad and a German Windows. With localized Mathcad versions I have the choice to us them in English or (in my case) German. Usually this affects keywords as well as error messages and help text (in contrary to Prime). My guess is that this runtimer error message is from the underlying .NET RTsystem and is simply handed over by Mathcad.

Maybe someone with Mathcad 14 can report if the error is present here, too.

[FDS]

This are the results for MC15 M010:

Filip

[Werner_E]

Thanks,

so the last assignment of V is OK even after a recalculate (Ctrl-F9) of the whole sheet?

[FDS]

Yes it is. I am using an english version of MC15 M010.

[VladimirN]

And here is a result in Mathcad 15 F000:

[Werner_E]

Tnx, so the first error seems to occur in all MC15 releases, the second in most and it depends on ....?

Hopefully PTC will address that in the next release.

[Werner_E]

According to PTC the bug will be fixed in MC15 M030