Function 'subs': how use?
1 次查看(过去 30 天)
显示 更早的评论
I have realized that the counts with this function 'subs' doing x(1) +1*x(2) and x(1) + 1*x(2) are differents, for example. The space in these expressions give me results differents.
Which the problem?
Which is correct? I think that the correct is x(1) +1*x(2) and not with the space.
Thanks.
JRC
0 个评论
回答(1 个)
Walter Roberson
2013-8-21
In the context of the [] operation,
x(1) +1*x(2)
would usually be interpreted as
(x(1)), (+1*x(2))
which is two entries.
x(1) + 1*x(2)
inside [] would be interpreted as one entry.
If you are not within the context of [] then the two should be the same.
5 个评论
Walter Roberson
2013-8-21
Do not eval() MuPAD expressions, such as are returned by sym() or subs(). MuPAD and MATLAB use different syntax rules and different operators. If you want to convert a MuPAD expression into executable MATLAB form, use matlabFunction() on the MuPAD expression -- but if you do not need to execute at the MATLAB level, keep expressions in MuPAD form. If you have a MuPAD expression which consists entirely of constants and you want to convert it to double precision, use double() on the MuPAD expression.
Please see also http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F . It looks to me as if you would be better off storing values in a struct than using eval() to generate new variable names.
另请参阅
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!