Hello,
This kind of problem has been reported before; see
<http://trac.sagemath.org/ticket/14821>.
You could try the workaround
sage: sage.calculus.calculus.maxima('keepfloat: false')
although this seems to be very slow (but maybe you expect it to be).
Peter
> Hi,
> I'm having problem with the code below,
>
> var('x t'); k=1.38*(10**-23) ; e1=0 ; e2 =170*k ; na=6.02*(10**23)
> a=0.1
> assume(x>a)
> u=1
> n=1 + floor(u)
>
> def DaRL(y,u):
> return (1/gamma(n-u))*diff(integral(y/((x-t)**(u-n+1)),t,a,x),x,n)
>
> z=exp(-e1/(k*t)) + 3*exp(-e2/(k*t))
> f=-t*k*log(z)
> s=-diff(f,t)
>
> somat=sum( (((t-a)**k)/factorial(k))*((derivative(s,t,k)).limit(t=a)) for
> k in [0..(u-1)])
>
> Dcaputo=DaRL((s-somat),u) ; Dcaputo
>
> Which, in this case, is the same as
>
> var('x t'); k=1.38*(10**-23) ; e1=0 ; e2 =170*k ; na=6.02*(10**23)
>
> z=exp(-e1/(k*t)) + 3*exp(-e2/(k*t))
> f=-t*k*log(z)
> s=-diff(f,t)
>
> Dcaputo=Diff(s,t) ; Dcaputo , changing the variable 't' to 'x'. If we put
> s=sin(t);cos(t); t; 1; or any function with a known derivative it works.
>
> But it's not working the way it should and I don't understand. When I ask
> Sage to do the code, Sage gives me this
>
> Traceback (most recent call last): def DaRL(y,u):
> File "", line 1, in <module>
>
> File "/tmp/tmpQtIbpd/___code___.py", line 18, in <module>
> exec compile(u'Dcaputo=DaRL((s-somat),u) ; Dcaputo
> File "", line 1, in <module>
>
> File "/tmp/tmpQtIbpd/___code___.py", line 10, in DaRL
> return (_sage_const_1
> /gamma(n-u))*diff(integral(y/((x-t)**(u-n+_sage_const_1 )),t,a,x),x,n)
> File
> "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/misc/functional.py",
> line 740, in integral
> return x.integral(*args, **kwds)
> File "expression.pyx", line 9302, in
> sage.symbolic.expression.Expression.integral
> (sage/symbolic/expression.cpp:38413)
> File
> "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py",
> line 688, in integrate
> return definite_integral(expression, v, a, b)
> File "function.pyx", line 429, in sage.symbolic.function.Function.__call__
> (sage/symbolic/function.cpp:5064)
> File
> "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py",
> line 173, in _eval_
> return integrator(*args)
> File
> "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/integration/external.py",
> line 21, in maxima_integrator
> result = maxima.sr_integral(expression, v, a, b)
> File
> "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/interfaces/maxima_lib.py",
> line 746, in sr_integral
> raise error
> RuntimeError: ECL says: In function GCD, the value of the second argument is
> 1.0
> which is not of the expected type INTEGER
>
> I don't know what this means. Can anyone give me a clue?
>
> Thanks.
>
>
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