[Scilab-users] evaluate matrix in a function

[Rafael Guerra]

diffcode_jacobian does not seem to accept multiple input points, but only one N-dimension point X:
  // Calling Sequence:
  //   J = diffcode_jacobian(f,x)
  //  x : a n-by-1 matrix of doubles, real, the point where to compute the derivatives

You cannot compare g and J, because the former is a function and the latter has type constant.
However you can compare J and V but the answer is false because of tiny numerical difference:
J==V
 ans  = 
  T T  
  T T  
  F T  
  T T  

J-V
 ans  =
    0.           0.  
    0.           0.  
  - 4.441D-16    0.  
    0.           0.

Rgds,
Rafael

-----Original Message-----
From: users [mailto:users-bounces at lists.scilab.org] On Behalf Of Hermes
Sent: Saturday, October 07, 2017 8:10 PM
To: users at lists.scilab.org
Subject: Re: [Scilab-users] evaluate matrix in a function

Hello
The H and g functions work. But the diffcode_jacobian (H, r) evaluation does
not accept the dot operator. Only redefining the H function (without dot
operators) will achieve the results

function val = HH(z)
    x=z(1);
    y=z(2); 
    val=(1.25*y-sqrt(abs(x)))^2+x^2-1; // switched *.^* to *^* 
endfunction;


t=[3. 1.]
disp(diffcode_jacobian(HH,t));

-->6.2783122
  -1.205127

J=[];
for k=1:size(r,"r")
    J(k,:)=diffcode_jacobian(HH,r(k,:)); 
  end
disp(J, "Jacobian");

-->Jacobian

   6.2783122  -1.205127 
   7.75            1.25     
   3.3915608   11.294873
   16.116117  -0.8210678

disp(and(J==g))
-->F   Why? The results of J and g look the same !!

g

   6.2783122  -1.205127 
   7.75             1.25     
   3.3915608   11.294873
   16.116117  -0.8210678

   
 J

   6.2783122  -1.205127 
   7.75            1.25     
   3.3915608   11.294873
   16.116117  -0.8210678

Gracias




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