Dear all,
I am new to sage and I have a problem with the integrate-command that I
cannot explain and whose error message I don't really understand. Here's
what it looks like: If I do quite simple integration
integral(exp(-300/x),x,0,120)
it works just fine. However, I would actually like to have a linear
function of x in the denominator, namely 0.064*x+14. This does not work, I
get the error message
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "_sage_input_36.py", line 10, in <module>
exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8
-*-\\n" +
_support_.preparse_worksheet_cell(base64.b64decode("bihpbnRlZ3JhbChleHAoLTMwMC8oLTAuMDY0KngrMTQpKSx4LDAsMTIwKSk="),globals())+"
\\n"); execfile(os.path.abspath("___code___.py"))
File "", line 1, in <module>
File "/tmp/tmpdbccuW/___code___.py", line 3, in <module>
exec compile(u'n(integral(exp(-_sage_const_300 /(-_sage_const_0p064
*x+_sage_const_14
)),x,_sage_const_0 ,_sage_const_120 ))
File "", line 1, in <module>
File
"/home/sage/sage-5.0/local/lib/python2.7/site-packages/sage/misc/functional.py"
, line 728, in integral
return x.integral(*args, **kwds)
File "expression.pyx", line 8745, in
sage.symbolic.expression.Expression.integral
(sage/symbolic/expression.cpp:33707)
File
"/home/sage/sage-5.0/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py"
, line 633, in integrate
return definite_integral(expression, v, a, b)
File "function.pyx", line 413, in sage.symbolic.function.Function.__call__
(sage/symbolic/function.cpp:4678)
File
"/home/sage/sage-5.0/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py"
, line 173, in _eval_
return integrator(*args)
File
"/home/sage/sage-5.0/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
"/home/sage/sage-5.0/local/lib/python2.7/site-packages/sage/interfaces/maxima_lib.py"
, line 747, in sr_integral
raise error
RuntimeError: ECL says: In function ZEROP, the value of the only argument is
((RAT SIMP) -0.064 1.0)
which is not of the expected type NUMBER
I already figured out that the problem is the decimal number. If I replace
0.064 by 64, it works fine again. However, I don't understand where the
problem is coming from. Sage is in general able to handle decimal numbers.
Why not in this case?
Any help would be greatly appreciated.
Uwe
PS: I hope I'm not double-posting, but I couldn't find my first post in the
list, so I send it again.-- -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
