Hi all,

next problem with matrices :(

(All with German local with comma as decimal delimiter)

Fill A1:C3 with
1       2       3
3       6       9
9,1     18      27
Calculate =MINVERSE(A1:C3)

I get
0,00000000-1.#NANE+000  #VALUE! #VALUE!
#NUM!   #NUM!   #VALUE!
#NUM!   #NUM!   #VALUE!

I guess, that the wrong notation in upper, left cell is already tracked in issue 114125. But I think, Calc should not return #NUM! or #VALUE! at all, but Err:502 (illegal argument), because the matrix is singular. The LU decomposition has a zero in the diagonal, so it is possible to detect this case. Excel and Gnumeric return #NUM! in the whole range.


Fill A1:D4 with
1       2       3       4
3       6       9       12
9       18,1    27      36
12,1    24      36      48
Calculate =MINVERSE(A1:D4)

I get in full science notation
-6,809917355371900E+001 -1,652892561983470E+001 0,000000000000000E+000 1,000000000000000E+001 -5,150539867109620E+001 -1,293916112956810E+001 9,999999999999860E+000 -5,177106436424810E-014 1,926351720312250E+015 -6,421172401040780E+014 1,670843776116550E-002 -1,408521303258110E+000 -1,444763790234140E+015 4,815879300780690E+014 -5,012531328320800E+000 -1,443609022556390E+000
which is in two decimal place notation
-68,10  -16,53  0,00    10,00
-51,51  -12,94  10,00   0,00
1926351720312250,00     -642117240104078,00     0,02    -1,41
-1444763790234140,00    481587930078069,00      -5,01   -1,44

If the user sees this result, he will be cautious. But it might be hidden as intermediate part of a larger formula. So the user does not notice that the result is totally wrong. LINEST needs calculating an inverse matrix for the statistics, but does of cause do not show the matrix but the statistics, so that the user might not detect, that the values are wrong. Gnumeric returns #ZAHL! errors and Excel returns the same wrong values as Calc.

Should I test the intermediate results in LINEST to catch this cases and return an error?

kind regards
Regina




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