symbolic calculation

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jack 2011-3-31

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https://ww2.mathworks.cn/matlabcentral/answers/4394-symbolic-calculation

采纳的回答： Walter Roberson

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Why do I get

>> a = sqrt(sym(2))

a =

                                      1/2
                                     2

instead of

a = 2^(1/2)

And I got >> H = sym(hilb(2))

H =

                   [       1.            0.500000000000000]
                   [                                      ]
                   [0.500000000000000    0.333333333333333]

instead of the fraction version. Is there any expert who can tell me how to set this? I use the mathlab 2010b.

采纳的回答

Walter Roberson 2011-3-31

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For the first point, try turning off pretty printing

evalin(symengine, 'PRETTYPRINT := FALSE');

I do not promise that it will work, though. If it doesn't, then

char(a)

should show you the linear form.

I don't know why the decimal form is given for the hilbert matrix. You could try, though,

evalin(symengine, 'linalg::hilbert(2)');

See the documentation

2010b cannot use Maple. If it doesn't know symengine, the implication would be that you do not have the symbolic toolbox, except then I would have expected it to fail on sym . I'm surprised you are getting anywhere with those commands if you don't have the symbolic toolbox.

jack 2011-3-31