Re: symbolic basic calculus help

[Richard Shadbolt]

Hi,

I have not used the symbolic package but the warnings i get are that 
passing floating point values to the symbolic process is a bad idea :

OctSymPy: Communication established.  SymPy v1.1.1.
warning: passing floating-point values to sym is dangerous, see "help sym"
warning: called from
    double_to_sym_heuristic at line 50 column 7
    sym at line 373 column 13
    mtimes at line 65 column 5
    /home/richard/DSP/2018 09 05 Octave issue bug forum.m at line 5 
column 3
warning: passing floating-point values to sym is dangerous, see "help sym"
warning: called from
    double_to_sym_heuristic at line 50 column 7
    sym at line 373 column 13
    mpower at line 76 column 5
    /home/richard/DSP/2018 09 05 Octave issue bug forum.m at line 5 
column 3
error: wrong type argument 'class'
error: eval: expecting std::string argument
error: parse error

As such, is there a way of running the process and not use floating 
point values ?

Also, the class error indicates that using floating points (numerical 
calculations) are not supported.

Regards,

Richard.


On 05/09/18 18:11, Jimmie713 wrote:
> clear all
> clc
> % Data
> syms t
> v=((1\(60^2))+0.8*t)^(-0.5);
> T0=0;
> T1=4;
> S0=0;
> %Velocity
> vT1=((1\(60^2))+0.8*T1)^(-0.5);
> % Position
> s=int(v, T0,T1);
> % Acceleration
> a=diff(v,t);
> t=T1;
> a=eval(a);
> % Display results
> vT1
> s
> a
> % End
>
> On octave it gives me a passing floating point error.
> In matlab it gives me the wrong value.  What the fuck am I doing wrong?
>
>
>
> --
> Sent from: http://octave.1599824.n4.nabble.com/Octave-General-f1599825.html