First off, why do you use Lambda. Just use Max(x, 5). This is definitely a bug. You can work around it by wrapping x in re(), like plot(Max(re(x), 5)). Perhaps plot should automatically do this if x is assumed to be real. Even so, it should not have this error regardless of assumptions.
Aaron Meurer On Sat, Jan 12, 2013 at 11:53 AM, Andre Holzner <[email protected]> wrote: > Dear sympy experts, > > I tried to plot a 'ramp function' as follows (sympy 0.7.2 on OSX): > > from sympy import * > x = Symbol('x',real = True) > f = Lambda(x, Max(x,5)) > plot(f(x), (x,0,10)) > > but I get the exception shown below on the last line. Should I be doing this > differently ? > When evaluating the function f at some values, it looks like it is returning > the correct values. > > best regards, > > Andre > > stack trace: > > Traceback (most recent call last): > File "/tmp/test.py", line 6, in <module> > plot(f(x), (x,0,10)) > File > "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/plotting/plot.py", > line 1165, in plot > plots.show() > File > "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/plotting/plot.py", > line 193, in show > self._backend.show() > File > "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/plotting/plot.py", > line 946, in show > self.process_series() > File > "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/plotting/plot.py", > line 838, in process_series > collection = LineCollection(s.get_segments()) > File > "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/plotting/plot.py", > line 461, in get_segments > f_start = f(self.start) > File > "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/plotting/experimental_lambdify.py", > line 204, in __call__ > result = self.lambda_func(args) > File "<string>", line 1, in <lambda> > TypeError: no ordering relation is defined for complex numbers > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/sympy/-/QHyOEPCLCt4J. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
