Re: Symbolica package warning: Using rat() heuristics for double-precision input (is this what you wanted?)

[Doug Stewart]

On Fri, Feb 17, 2017 at 6:00 AM, Stephen Biggs <address@hidden> wrote:

Hi,

I am using the symbolic package (so include `pkg load symbolic` before the following commands if necessary). If I run:

    syms x
    fsym = x * cos(x)
    fsymder = diff(fsym)
    vpa(subs(fsymder, x, 3.141592654), 8)

Then I get the following:

    warning: Using rat() heuristics for double-precision input (is this what you wanted?)
    warning: called from
        sym at line 256 column 9
        subs at line 118 column 7
    ans = (sym) -1.0000000

So the answer is correct but there is that warning about rat() heuristics. How can I fix it so that the warning is not given. NB: I would rather **fix** the code so that the warning is not raised rather than just supressing the warning with `warning('off', '<warning_id>')`. However, if the former is not possible, then I will accept the latter but I need to know the warning ID.

Many thanks,

Steve

Try these ideas

 syms x

    fsym = x * cos(x)

    fsymder = diff(fsym)

    

    xx=sym(pi)

    

    xxx=sym( "3.14159");

    

    

    syms q

    q=2.777123

    qq=mat2str(q)

    ww=sym(qq)

    

    vpa(subs(fsymder, x, xx), 8)

--

DAS