how to solve a equation

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hua
hua 2013-12-14
评论： Walter Roberson 2013-12-15
I have a cell array,its elements are all of expression with symbol variables a{i,j}.
for example
cell array:f{n},
*f{1} = 3*b{3,5}*b{1,2} + 4*b{2,2} + ...+b{i,j},
f{2} = 4*b{3,5} + 4*b{6,2}*b{1,1} + ...+, ;
f{n} = b{2,3} + b{7,8} +;
f{n} = 0;*
I know every .expression of f{i},
if I use fsolve function,I have to display all equations,for large i, it is impractical. so is there any other method to get every b{i,j}'s value ,
can i use fsolve like these fsolve(f);
thank you!!
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hua
hua 2013-12-15
I dont't want to write down every expressions,
for example,the number of equation exceeds 100
Walter Roberson
Walter Roberson 2013-12-15
What form do you have them available in?

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Matt J
Matt J 2013-12-14
编辑：Matt J 2013-12-14
if I use fsolve function,I have to display all equations,for large i, it is impractical.
You should be using vectorized commands to generate f, not scalar expressions. For example, if I had equations
f(1)=x(1)+1
f(2)=x(2)+2
f(3)=x(3)+3
...
f(N)=x(N)+N
I would generate f in the single statement,
f=x+1:length(x)
regardless of the size of N.
  2 个评论
hua
hua 2013-12-15
thank you for answer.
I mean I had already get every expression of f{i},and I want to solve these equations.
for example use fsolve function,but this means I have to write every equation,and the
number of f{i} is over 100;I don't want write down every equation,how can I solve these
equations?
Matt J
Matt J 2013-12-15
编辑：Matt J 2013-12-15
but this means I have to write every equation,
No, I already told you that you don't have to. You must look for an alternative matrix/vector valued way of expressing f.
Also, if you already "get every expression", it means you've already written them down, or that you have them in some sort of executable form.

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