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A
Anonymous
February 17, 2010
Question

Integral not evaluated with float integrand

  • February 17, 2010
  • 2 replies
  • 4010 views
Found another bug presumeably with Mupad.

Even very simply integrals with at least one variable limit dont' get evaluated.

See attached picture.

Assuming the limit or the variable x as real does not help.

Using MC_14_M030.

RMix

2 replies

T
TomGutman1-Visitor
1-Visitor
February 17, 2010
The use of a number with a decimal point in an expression forces float (numeric) evaluation (part of the specifications for the symbolic processor). With variable limits, such a numeric evaluation cannot be done, and it leaves the original integral expression.
__________________
� � � � Tom Gutman
R
RichardJ19-Tanzanite
19-Tanzanite
February 17, 2010
On 2/17/2010 8:26:36 PM, Tom_Gutman wrote:
>The use of a number with a
>decimal point in an expression
>forces float (numeric)
>evaluation (part of the
>specifications for the
>symbolic processor). With
>variable limits, such a
>numeric evaluation cannot be
>done

Why?

Richard
T
TomGutman1-Visitor
1-Visitor
February 17, 2010
>>Why?<<

Because the result depends on the (unknown) value of the limit.
__________________
� � � � Tom Gutman
R
RichardJ19-Tanzanite
19-Tanzanite
February 17, 2010
That's bug alright. A rather lame one, because if you change the 2 in your first example to an undefined variable name such as xxx the integral evaluates just fine. So it can evaluate the integral with no problem, it just can't substitute a floating point number afterward.

Richard
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