Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

Can't solve equation with abs in the terms

Hi, I have a problem with this system:

f(x,y)=(1+y-a*abs(x),b*x)
solve([f[0]==x, f[1]==y], x,y)

It gives me this big error:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "_sage_input_14.py", line 10, in <module>
    exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 -*-\\n" + _support_.preparse_worksheet_cell(base64.b64decode("c29sdmUoW2ZbMF09PXgsIGZbMV09PXldLCB4LHkp"),globals())+"\\n"); execfile(os.path.abspath("___code___.py"))
  File "", line 1, in <module>

  File "/tmp/tmpfPvSBx/___code___.py", line 3, in <module>
    exec compile(u'solve([f[_sage_const_0 ]==x, f[_sage_const_1 ]==y], x,y)
  File "", line 1, in <module>

  File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/relation.py", line 864, in solve
    sol_list = string_to_list_of_solutions(repr(s))
  File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/symbolic/relation.py", line 539, in string_to_list_of_solutions
    v = symbolic_expression_from_maxima_string(s, equals_sub=True)
  File "/usr/lib/sagemath/local/lib/python2.7/site-packages/sage/calculus/calculus.py", line 1893, in symbolic_expression_from_maxima_string
    return SRM_parser.parse_sequence(s)
  File "sage/misc/parser.pyx", line 533, in sage.misc.parser.Parser.parse_sequence (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:4832)
  File "sage/misc/parser.pyx", line 549, in sage.misc.parser.Parser.parse_sequence (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:4699)
  File "sage/misc/parser.pyx", line 613, in sage.misc.parser.Parser.p_sequence (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:5440)
  File "sage/misc/parser.pyx", line 645, in sage.misc.parser.Parser.p_list (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:5788)
  File "sage/misc/parser.pyx", line 622, in sage.misc.parser.Parser.p_sequence (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:5562)
  File "sage/misc/parser.pyx", line 712, in sage.misc.parser.Parser.p_eqn (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:6386)
  File "sage/misc/parser.pyx", line 752, in sage.misc.parser.Parser.p_expr (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:6766)
  File "sage/misc/parser.pyx", line 786, in sage.misc.parser.Parser.p_term (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:7028)
  File "sage/misc/parser.pyx", line 829, in sage.misc.parser.Parser.p_factor (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:7465)
  File "sage/misc/parser.pyx", line 857, in sage.misc.parser.Parser.p_power (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:7610)
  File "sage/misc/parser.pyx", line 916, in sage.misc.parser.Parser.p_atom (/usr/lib/sagemath//src/build/cythonized/sage/misc/parser.c:8304)
  File "sage/symbolic/function.pyx", line 471, in sage.symbolic.function.Function.__call__ (/usr/lib/sagemath//src/build/cythonized/sage/symbolic/function.cpp:6627)
TypeError: cannot coerce arguments: no canonical coercion from <type 'list'=""> to Symbolic Ring

What can I do?