sage riemann sum code example

Example: riemann sum sagemath

sage -t  -force_lib devel/sage/doc/en/constructions/calculus.rst
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File "/mnt/usb1/scratch/jdemeyer/merger/sage-4.6.2.alpha2/devel/sage-main/doc/en/constructions/calculus.rst", line 204:
    sage: f.trapezoid(4)
Expected:
    Piecewise defined function with 4 parts, [[(0, 1/2), 1/2*x],
    [(1/2, 1), 9/2*x - 2], [(1, 3/2), 1/2*x + 2],
    [(3/2, 2), -7/2*x + 8]]
Got:
    doctest:1: DeprecationWarning: _word_content is deprecated, use riemann_sum instead
    Piecewise defined function with 4 parts, [[(0, 1/2), 1/2*x], [(1/2, 1), 9/2*x - 2], [(1, 3/2), 1/2*x + 2], [(3/2, 2), -7/2*x + 8]]
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