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2016-05-02 18:46:09 -0600 received badge  Student (source)
2016-05-02 03:46:44 -0600 asked a question integrate and simplify

Hello, Here is a list of command lines that used to work fine one year ago, but today, it's not :

> fksin=piecewise([[(-2,0),f1(t)*sin(k*w*t)],[(0,1),f2(t)*sin(k*w*t)],[(1,2),f3(t)*sin(k*w*t)]])
>var('t k')
>assume(k,'integer')
>f1(t)=0
>f2(t)=t
>f3(t)=2-t
>T=4
>w=2*pi/T
>f=piecewise([[(-2,0),f1],[(0,1),f2],[(1,2),f3]])
>fkcos=piecewise([[(-2,0),f1(t)*cos(k*w*t)],[(0,1),f2(t)*cos(k*w*t)],[(1,2),f3(t)*cos(k*w*t)]])
>bkf=(2/T)*integral(fksin,t,-T/2,T/2)
>bkf.simplify_trig()
4*sin(1/2*pi*k)/(pi^2*k^2)

But today, the answer is : Error in lines 1-1 Traceback (most recent call last): File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 905, in execute exec compile(block+'\n', '', 'single') in namespace, locals File "", line 1, in <module> File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/misc/functional.py", line 664, in integral return x.integral(args, *kwds) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/functions/piecewise.py", line 837, in integral F = self.integral(x) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/functions/piecewise.py", line 877, in integral area += fun.integral(x, start, end) File "sage/symbolic/expression.pyx", line 11352, in sage.symbolic.expression.Expression.integral (/projects/sage/sage-6.10/src/build/cythonized/sage/symbolic/expression.cpp:60288) return integral(self, args, *kwds) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py", line 761, in integrate return definite_integral(expression, v, a, b, hold=hold) File "sage/symbolic/function.pyx", line 988, in sage.symbolic.function.BuiltinFunction.__call__ (/projects/sage/sage-6.10/src/build/cythonized/sage/symbolic/function.cpp:11343) res = super(BuiltinFunction, self).__call__( File "sage/symbolic/function.pyx", line 503, in sage.symbolic.function.Function.__call__ (/projects/sage/sage-6.10/src/build/cythonized/sage/symbolic/function.cpp:7110) res = g_function_evalv(self._serial, vec, hold) File "sage/symbolic/function.pyx", line 1059, in sage.symbolic.function.BuiltinFunction._evalf_or_eval_ (/projects/sage/sage-6.10/src/build/cythonized/sage/symbolic/function.cpp:12072) return self._eval0_(args) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/symbolic/integration/integral.py", line 176, in _eval_ return integrator(args) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/symbolic/integration/external.py", line 24, in maxima_integrator result = maxima.sr_integral(expression, v, a, b) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/interfaces/maxima_lib.py", line 776, in sr_integral return max_to_sr(maxima_eval(([max_integrate],[sr_to_max(SR(a)) for a in args]))) File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage/interfaces/maxima_lib.py", line 1630, in max_to_sr args=[max_to_sr(a) for a in max_args] File "/projects/sage/sage-6.10/local/lib/python2.7/site-packages/sage ... (more)