List of matrices bug Algebra

hawe shared this problem 10 months ago
New

In the other way round regarding


https://help.geogebra.org/t...


LE={{{1, 0, 0}, {0, 1, 0}, {0, 2, 1}}, {{1, 0, 0}, {-1, 1, 0}, {0, 0, 1}}, {{1, 0, 0}, {0, 1, 0}, {1, 0, 1}}}

invert members of matrix list by

Sequence(2 * Identity(3) - Element(LE, k),k,1,3)


fails in algebra window

/fCofDdXV1Q0NDmoaUD8hajXQ67fP5yq68lSMajVb53jE+ny8ajWqU+fj4eCXPDaORSqU6OjrYp+spEQgEqvnaJRwO4292MTc319jYyPfGbFlA1gAAACYAZA0AAGACQNYAAAAmAGQNAABgAkDWAAAAJgBkDQAAYAJA1gAAACYAZA0AAGACQNYAAAAmAGQNAABgAkDWAAAAJgBkDQAAYAJA1gAAACZgW9bPAQAAAEZlW9YfGpLnnntuBQAAoOoxh6z1vv4AAADQmf8Pn3BKOaag35QAAAAASUVORK5CYII=

seems to stuck on last index


BTW: should not be possible to do the job by

2 * Identity(3) - LE

Comments (5)

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1

Inverting list LE is also different in CAS in AlgebraView

CAS: LE^-1 is correct and AlgebraView LE^-1=undefined

perhaps important LE is defined in CAS


https://ggbm.at/dc27zpw5

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invert(matrix) is the right form, not invert(list) you can do l1 = Zip(Invert(2Identity(3) - m), m, LE)


Zip((2Identity(3) - m)⁻¹, m, LE) works also

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We have different handling of LE^-1 in CAS (inverting members of LE) and LE^-1 in AlgebraView (undefined). I also tried Zip, but was not successful in CAS but OK in ALgebraView - shouldn't we have consistent handling?


/wfifkfbUhwSwQAAAABJRU5ErkJggg==

invert(M) = 2 Identity(n)-M


I do not need both (Elementarmatrices) - even your postet form do not work (5.0.518)...


BTW:


Product(LE) do not work in CAS - do you see an alternative way (not AlgebraView - is OK there)

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there is ever two ways for operations on list: as list or as matrix

this seems change in CAS or algebra view

you can try Product(LE(n),n,1,Length(LE)) in CAS

or Product(element(LE,n),n,1,Length(LE)) if there is problem with short notation


I think there is a bug with the deep of zip of lists in CAS

/Bzx3Px32daJCAAAAAElFTkSuQmCC

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Thank you, great,

I have not seen, not expected, to use Product in this way - it works, I cannot use short index notation (AlgebraView) because I want to have variables in matrices

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