can't use KummerU function

Hi, When I try to use builtin kummerU function, it gives me "Undefined function 'kummerU' for input arguments of type 'double'." Needed package is installed, and I don't understand why can't the function use real number instead of complex with zero imaginary part.

Help!

Daniel

Answer 1

[Friedrich]

Hi,

kummerU is a Symbolic Math Toolbox function, so you can't simply call:

>> kummerU(1/3, 2.0, -50)
Undefined function 'kummerU' for input arguments of type 'double'.

You have to call:

>> evalin(symengine,'kummerU(1/3, 2.0, -50)')

ans =

0.13511493810668281560142994786047 - 0.23402593766229884316074691432347*i

Or use feval:

>> feval(symengine,'kummerU',1/3, '2.0', -50)

ans =

0.13511493810668281560142994786047 - 0.23402593766229884316074691432347*i

I used '2.0' in order to get a floating-point value otherwise you would get:

>> feval(symengine,'kummerU',1/3, 2.0, -50)

ans =

kummerU(1/3, 2, -50)

This is explained here:

http://www.mathworks.com/help/symbolic/call-built-in-mupad-functions-from-the-matlab-command-window.html

[Daniel]

Thanks a lot! When I want to use hypergeom function, should I do it in the same way?

Daniel

[Friedrich]

hypergeom can be called directly (because its available as m file). No need to do it like above.

[Daniel]

I try to use hypergeom directly, but it returns the following error:

Error using mupadmex
Internal error with symbolic engine. Please quit and restart MATLAB.

Error in sym/hypergeom (line 1084)
        hSym = mupadmex('symobj::map', args{1}.s, 'symobj::hypergeom',...

Error in hypergeom (line 35)
   h = double(hypergeom(n,d,sym(z)));

Error in momentum (line 7)
x=hypergeom(p+nu+1,nu+1,alpha/2);

Error in Putprice (line 47)
    Def=1-exp(-integral(bfunc,0,T))*(x^2/tau)^(1/(2*abs(beta)))*momentum(-1/(2*abs(beta)),delta,x^2/tau);

Error in LSQDiff (line 12)
   Diff(:,i)= mktprice(:,i)-Putprice(S,K,T(i),x(1),x(2));

Error in C:\Program Files\MATLAB\MATLAB Production
Server\R2012b\toolbox\shared\optimlib\finDiffEvalAndChkErr.p>finDiffEvalAndChkErr
(line 26)

Error in C:\Program Files\MATLAB\MATLAB Production
Server\R2012b\toolbox\shared\optimlib\finitedifferences.p>finitedifferences (line
128)

Error in sfdnls (line 89)
   [J,~,~,numEvals] = finitedifferences(x,fun,[],lb,ub,valx,[],[], ...

Error in snls (line 177)
   [A,findiffevals] = sfdnls(xcurr,fvec,Jstr,group,[],funfcn{3},l,u,...

Error in lsqncommon (line 175)
    [xC,FVAL,LAMBDA,JACOB,EXITFLAG,OUTPUT,msgData]=...

Error in lsqnonlin (line 232)
[xCurrent,Resnorm,FVAL,EXITFLAG,OUTPUT,LAMBDA,JACOB] = ...

Please help me solve this problem!

[Friedrich]

Hi,

it seems like you compiled your MATLAB code into a generic CTF? Is this correct? If so, Symbolic Math TB functions can't be compiled.