error in inverting matrix - Сообщения
#1 Опубликовано: 11.02.2010 15:28:00
hi
i was trying to invert a matrix with smath winxp 2010-feb10 version.
It gives me an error that "matrix is noninvertible (determinant equals zero)".
the determinant is not zero, i have checked. i have tried the M^-1 and invert(M) too. but gives the same error.
if i do this, then it works, calculates the result:
M:=...
M^-1= RESULT
if I do this, then it does not work:
M:=...
M2:=M^-1
M2= ERROR
i was trying to invert a matrix with smath winxp 2010-feb10 version.
It gives me an error that "matrix is noninvertible (determinant equals zero)".
the determinant is not zero, i have checked. i have tried the M^-1 and invert(M) too. but gives the same error.
if i do this, then it works, calculates the result:
M:=...
M^-1= RESULT
if I do this, then it does not work:
M:=...
M2:=M^-1
M2= ERROR
#2 Опубликовано: 11.02.2010 15:46:07
M=1/sqrt(2)*mat(1,-1,0,0,0,0,1,-1,1,1,0,0,0,0,1,1,4,4)
det(M)=-1 so it is not zero
if i change the matrix, to get a different determinant, not -1, then it wors.
det(M)=-1 so it is not zero
if i change the matrix, to get a different determinant, not -1, then it wors.
#3 Опубликовано: 11.02.2010 15:49:04
Hello.
I can't reproduce this error with my matrices:
Could you please send your full example to support[at]smath[dot].info?
Best regards, Andrey Ivashov.
I can't reproduce this error with my matrices:
Could you please send your full example to support[at]smath[dot].info?
Best regards, Andrey Ivashov.
#4 Опубликовано: 11.02.2010 15:53:19
OK, I see now, thanks. Will check in 5 hrs.
#5 Опубликовано: 11.02.2010 21:01:07
Figured out that this error was in previous versions of SMath Studio as well when trying to evaluate symbolically:
[MATH](1/sqrt(2)*mat(1;-1;0;0;0;0;1;-1;1;1;0;0;0;0;1;1;4;4))^{-1}—#[/MATH]
Starting work to fix it.
[MATH](1/sqrt(2)*mat(1;-1;0;0;0;0;1;-1;1;1;0;0;0;0;1;1;4;4))^{-1}—#[/MATH]
Starting work to fix it.
#6 Опубликовано: 11.02.2010 22:01:01
ok,
thanks.
thanks.
#7 Опубликовано: 15.02.2010 01:18:02
Here is modified version of SyLib.dll file for SMath Studio 0.87 where this bug fixed: https://smath.com/files/Download/hkzMV (just unpack it and replace original SyLib.dll from Program Files/SMath/SMath Studio folder).
You can use it till next version of the program will be released.
Regards.
You can use it till next version of the program will be released.
Regards.
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