()-indexing must appear last in an index expression

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Misa
Misa 2013-1-9
评论： Walter Roberson 2016-12-2
I get this error related to this line of code:
A(l,c)=A(l,c)+(b(l)(D(1,h))*b(c)(D(1,h)))
b is a vector that in each position has a function(like x^2), and D is a matrix whose all components are numbers. What i whant to do here is calculate the value of the functon b(l) on D(l,h)

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采纳的回答

Philip Borghesani
MATLAB does not support arrays of function handles (some earlier versions did what version are you using?). Use a cell array containing the function handles then you should be able to use the line:
A(l,c)=A(l,c)+(b{l}(D(1,h))*b{c}(D(1,h)))
Note changing ( to { for accessing b.

更多回答（3 个）

Daniel Shub
Daniel Shub 2013-1-9
What i whant to do here is calculate the value of the functon b(l) on D(l,h)
The simple answer is that despite the fact that you want to do this, you cannot. There are hacks, but the simplest way is
temp1 = b(l);
temp2 = b(c);
A(l,c)=A(l,c)+temp1(D(1,h))*temp2(D(1,h));
  2 个评论
Misa
Misa 2013-1-9
I tried that but I get another error:
??? Attempted to access temp1(-2); index must be a positive integer or logical.
So I think 'it' isnt recognizing temp1 as a function but as an array
Walter Roberson
Walter Roberson 2013-1-9
编辑：Walter Roberson 2013-1-9
What datatype is b ? What does class(b) show ?

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Jan
Jan 2013-1-9
编辑：Jan 2013-1-9
If you use a modern Matlab version, at least >= 2009a, you can store function handles in a cell only. Then this should work:
A(l,c) = A(l,c) + (b{l}(D(1,h)) * b{c}(D(1,h)))
Using an array for function handles has been available for a short time only, because it causes an ambiguity for e.g. "F(1)": Is (1) the argument of the function or the index of the functionhandle array?
Utaibah Mustafa
Utaibah Mustafa 2016-12-2
编辑：Walter Roberson 2016-12-2
??? Error: ()-indexing must appear last in an index expression
p=0.05;
i=0.01;
d=0;
sim('utaibah')
plot(time,PV)
hold on
p=0.1;
i=0.01;
d=0;
sim('utaibahm')
plot(time,PV,'r')
p=0.2;
i=0.01;
d=0;
sim('utaibahmus')
plot(time,PV,'k')
  2 个评论
Walter Roberson
Walter Roberson 2016-12-2
You appear to be using sim() on three Simulink models. Do one or more of them have MATLAB Function Blocks, or arithmetic blocks, or Level 2 Functions programmed in MATLAB? The problem is probably in one of the models.
We will probably need the three models to test with.
Question: does utaibah have a To Workspace block that is creating PV, or did you define PV in something you did not show here?

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