What is wrong with this code? (eval function, symbolic toolbox, 3 super short lines)
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This code worked in Matlab 2010 and 2011. Since I upgraded it doesn't work. What's wrong with it? I have no idea how to fix this. All I want to do is substitute in the alternative expression for "u" into "equation". This should not be so hard!
syms u uBar uSigma
equation = diff(sym('a(u)'),u);
subs(equation,'u',uBar*uSigma)
Thanks for any help.
EDIT: The error I receive is
Error using mupadmex
Error in MuPAD command: The variable is invalid. [stdlib::diff]
Error in sym/subs>mupadsubs (line 146)
G = mupadmex('symobj::fullsubs',F.s,X2,Y2);
Error in sym/subs (line 119)
G = mupadsubs(F,X,Y);
Error in MatlabExample (line 3)
subs(equation,'u',uBar*uSigma)
6 个评论
Jan
2013-3-7
Please explain "it doesn't work" with any details. Solving a problem is easier than guessing it. Thanks.
Oleg Komarov
2013-3-7
Error using mupadmex
Error in MuPAD command: The variable is invalid. [stdlib::diff]
Error in sym/subs>mupadsubs (line 139)
G = mupadmex('symobj::fullsubs',F.s,X2,Y2);
Error in sym/subs (line 124)
G = mupadsubs(F,X,Y);
Theodore
2013-3-7
Theodore
2013-3-11
Oleg Komarov
2013-4-7
Have you tried submitting a support request?
Walter Roberson
2013-4-7
What result is shown for "equation" ?
Does it change if you use
subs(equation, u, uBar*uSigma)
with the u not quoted ?
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