How to calculate all the square roots of a matrix?
11 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
I have a matrix [5/8 3/8; 3/8 5/8] and it has more than one square root. If I perform sqrtm on it, it returns only one square root. How do I obtain all of its square roots?
0 Kommentare
Antworten (2)
Walter Roberson
am 19 Dez. 2017
x = sym('x', [2 2]);
xsq = x^2;
sol = solve(xsq == [5/8 3/8; 3/8 5/8]);
all_roots = arrayfun(@(x11, x12, x21, x22) [x11,x12;x21,x22], sol.x1_1, sol.x1_2, sol.x2_1, sol.x2_2, 'uniform', 0);
2 Kommentare
Walter Roberson
am 22 Dez. 2017
T = sqrt(sym(2)); U = [-1/T -1/T;-1/T/2 1/T/2] double(U) %verify that U is the matrix you are talking about U^2
The result is
[ 3/4, 1/4]
[ 1/8, 3/8]
which is not your original matrix, so the matrix you indicate is not a square root of the original matrix.
Siehe auch
Kategorien
Mehr zu Creating and Concatenating Matrices finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!