Evaluating a derivative of an unknown function
 
  
 
  
 
 
 
 
 
 
    
        
        asked 6 years ago  
 
 Luis Escudero gravatar image  
 
 
 
 
 
I need to evaluate the derivative of a certain unknown function, but instead of doing this what I get is the expression with a change in the name of the variable.
 
My example
 
z,l = var('z,l')  
g = function('g', nargs=1)(z)    
g_prime = g.derivative(z)(z)    
g_prime(l)
 
So the output for that code is  \frac{\partial}{\partial l} g (l) .
 
Instead, I would like \frac{\partial}{\partial z} g(l)
 
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Comments
1
This does not quite do what you're asking, but is close:
sage: from sage.symbolic.constants import Constant
sage: l = Constant('l').expression()
sage: g.diff(z)(l)
D[0](g)(l)
rburing gravatar imagerburing (
    
        6 years ago
    )
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