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Is it possible to get the derivative of a function_handle as a other function_handle?

Like:

  fun1 = @(x) x^2;
  % do that ...
  disp(fun2);
    @(x) x*2

I know how to find the derivative of a symbolic function but I can't convert a function_handle to a symbolic function.

I'm new to matlab and I couldn't find any way on doing that. Thanks in advance.

Nzbuu
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user839791
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4 Answers4

1
syms x 
f = @(x) x^2 + 1; 
diff(f,x)

Ans: 

2*x + 1
Msh
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1

The short answer is "No." MATLAB has no idea what the contents of the function_handle mean in a symbolic sense. You're better off creating it using syms in first place.

A longer answer would be either to use the Symbolic Math Toolbox, as suggested by @A Danesh, or an approximation, as suggested by @Andrey.

However, if you're always working with polynomials, then you can store the coefficients as an array and use the following functions:

  • polyval to evaluate
  • conv to multiply
  • deconv to divide
  • polyder to differentiate
  • polyint to integrate
Nzbuu
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0

You can get an approximation function: 

 delta = 0.0001;
 d = @(x)( (fun1(x+delta) - fun1(x))./delta)
Andrey Rubshtein
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0

you can't analytically from a function handle.

but if you got the symbolic math toolbox you can derivate the symbolic function and create a function handle from the result.

bdecaf
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