piecewise defined function via def

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Anonymous

I've made the following experiment with Sage:

    def f(x):

        if (0<= x<= 1/2):
            return 1
        else:
            return 0 
assume(0<= x<= 1/2)  
show(f(x))  
show(f(1/3))

However I get outputs 0 and 1 respectively. Can someone clarify please? Thanks.

Comments

tmonteil ( 7 years ago )

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nbruin
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Looks like double inequalities aren't parsed properly by "assume":

sage: assume(0<= x<= 1/2)
sage: bool(0<=x<=1/2)
False
sage: assume(0<=x)
sage: assume(x<=1/2)
sage: bool(0<=x<=1/2)
True

Note that assume does not parse anything, it takes a symbolic expression that silently fails, see my answer to the duplicate question

tmonteil ( 7 years ago )

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Asked: 7 years ago

Seen: 754 times

Last updated: Feb 12 '18