error using sym/subs with logical operation
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
alice W
am 4 Jul. 2019
Kommentiert: Stephen23
am 4 Jul. 2019
Hello,
here is my code
syms x1 x2
aa=x1 == 0 & x2 == 0
subs(aa, [0.5 0.5])
the result is
ans =
[ 1/2 == 0 & x2 == 0, 1/2 == 0 & x2 == 0]
I wanna get result like this
1/2==0 & 1/2==0
What's the problem?
Thanks.
0 Kommentare
Akzeptierte Antwort
Stephan
am 4 Jul. 2019
Bearbeitet: Stephan
am 4 Jul. 2019
1
You only substitute x1 - you have to substitute them both. Try:
syms x1 x2
aa= x1 == 0 & x2 == 0
aa = subs(aa,[x1 x2], [0.5 0.5])
which results in:
aa =
1/2 == 0
2
Or use vectors, which doesnt work together with "&":
syms x1 x2
aa=[x1 == 0, x2 == 0]
aa = subs(aa,[x1 x2], [0.5 0.5])
result is:
aa =
[ 1/2 == 0, 1/2 == 0]
3
If you use 2 different numbers:
syms x1 x2
aa= x1 == 0 & x2 == 0
aa = subs(aa,[x1 x2], [0.5 0.6])
you get:
aa =
1/2 == 0 & 3/5 == 0
because Matlab can not simplify this, like it did in the first example.
3 Kommentare
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Conversion Between Symbolic and Numeric 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!