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Error in evaluating an inverse Matrix

vlehner
13-Aquamarine

Error in evaluating an inverse Matrix

Hi,

When evaluating the inverse Matrix of A, i got two different results in MP4 using the symbolical evaluation and the evaluation with "=".

Creating the same inverse Matrix in MC15 does give the same correct results by evaluating the same way like above.

 

Has somebody the same experience when calculating Matrices in Prime?

See attachement please.

 

Volker
1 ACCEPTED SOLUTION

Accepted Solutions

I can't open your file and just gave it a try with Prime 3.0.

Here all ist OK as it should be.

Only if I set the math format to "Decimal" with 0 decimals displayed, I get the result seen in Valery's pictures.

Bild.png

So unless you accidentally used that misleading setting in your sheet, its definitely a severe bug introduced after P30.

 

What do you get if you evaluate A*A^-1= ? If you still get the identity, its just a display probem, otherwise its an even more fatal bug.

 

View solution in original post

9 REPLIES 9

I think it is a bug in Mathcad Prime 4!

Mat-Err.png

All OK in Mathcad 15

Mat-Not-Err.png

I can't open your file and just gave it a try with Prime 3.0.

Here all ist OK as it should be.

Only if I set the math format to "Decimal" with 0 decimals displayed, I get the result seen in Valery's pictures.

Bild.png

So unless you accidentally used that misleading setting in your sheet, its definitely a severe bug introduced after P30.

 

What do you get if you evaluate A*A^-1= ? If you still get the identity, its just a display probem, otherwise its an even more fatal bug.

 


@WernerExinger wrote:

I can't open your file and just gave it a try with Prime 3.0.

 

But I can - it is for my Mathcad Mad House!

IM.png 


 

vlehner
13-Aquamarine
(To:Werner_E)


@WernerExinger wrote:

So unless you accidentally used that misleading setting in your sheet, its definitely a severe bug introduced

 

What do you get if you evaluate A*A^-1= ? If you still get the identity, its just a display probem, otherwise its an even more fatal bug.

 


That's it!

It's not a bug, it was my careless of the setting of the displayment of numbers.

if i set the display to 3 decimals all is ok.

08-09-2017 17-36-24.jpg

Passt!

Thanks Werner.

Volker


@vlehner wrote:

@WernerExinger wrote:

So unless you accidentally used that misleading setting in your sheet, its definitely a severe bug introduced

 

What do you get if you evaluate A*A^-1= ? If you still get the identity, its just a display probem, otherwise its an even more fatal bug.

 


That's it!

It's not a bug, it was my careless of the setting of the displayment of numbers.

if i set the display to 3 decimals all is ok.

08-09-2017 17-36-24.jpg

Passt!

Thanks Werner.


We say in this case: "И на старуху бывает проруха!" 

vlehner
13-Aquamarine
(To:ValeryOchkov)


@ValeryOchkov wrote:



We say in this case: "И на старуху бывает проруха!" 


Good old Google translator says: "Und die alte Frau ist proruha"

Smiley LOLSmiley LOLSmiley Tongue

Volker

OK, so this time we can't blame Prime  🙂

vlehner
13-Aquamarine
(To:Werner_E)


@WernerExinger wrote:

OK, so this time we can't blame Prime  🙂


it's sometimes tricky with the settings, especially when copying files and changing them.

Volker
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