How to plot? Having a issue.. Need to plot evolution of the norm of a symbolic matrix for t=0 to 1.

syms t

PHI=[ 1, t, t/3 - (2*exp(-3*t))/9 + 2/9, (2*t)/3 + (2*exp(-3*t))/9 - 2/9;

0, 1, (5*exp(-3*t))/12 - (3*exp(t))/4 + 1/3, 2/3 - exp(t)/4 - (5*exp(-3*t))/12;

0, 0, exp(-3*t)/4 + (3*exp(t))/4, exp(t)/4 - exp(-3*t)/4;

0, 0, (3*exp(t))/4 - (3*exp(-3*t))/4, (3*exp(-3*t))/4 + exp(t)/4];

N=norm(PHI);

t=0:0.00001:1;

plot(t,N)

Answer:

Error using plot

Data must be numeric, datetime, duration or an array

convertible to double.

Error in Q22 (line 8)

plot(t,N)

Answer 1

[Stijn Haenen]

you should use fplot or ezplot (https://nl.mathworks.com/help/symbolic/ezplot.html) to plot a 'sym' variable.

Answer 2

[Shauvik Das]

syms t
PHI=[ 1, t, t/3 - (2*exp(-3*t))/9 + 2/9, (2*t)/3 + (2*exp(-3*t))/9 - 2/9;
    0, 1, (5*exp(-3*t))/12 - (3*exp(t))/4 + 1/3, 2/3 - exp(t)/4 - (5*exp(-3*t))/12;
    0, 0, exp(-3*t)/4 + (3*exp(t))/4, exp(t)/4 - exp(-3*t)/4;
    0, 0, (3*exp(t))/4 - (3*exp(-3*t))/4, (3*exp(-3*t))/4 + exp(t)/4];
N=norm(PHI);

ezplot(N,[0,1])






Still showing error: 
Dimension argument is not supported when two input
arrays are provided.

Error in inline/feval (line 33)
        INLINE_OUT_ = inlineeval(INLINE_INPUTS_,
        INLINE_OBJ_.inputExpr, INLINE_OBJ_.expr);

Error in ezplotfeval (line 51)
    z = feval(f,x(1));

Error in ezplot>ezplot1 (line 486)
    [y, f, loopflag] = ezplotfeval(f, x);

Error in ezplot (line 158)
                [hp, cax] = ezplot1(cax, f{1}, vars,
                labels, args{:});

Error in sym/ezplot (line 78)
      h = ezplot(fhandle(f),varargin{:});%#ok<EZPLT>

Error in Q2 (line 10)
ezplot(N,[0,1]);

Answer 3

[Stijn Haenen]

Your PHI is a 4x4 matrix, do you want to plot 16 function against t?

That can be done with:

syms t 
PHI=[ 1, t, t/3 - (2*exp(-3*t))/9 + 2/9, (2*t)/3 + (2*exp(-3*t))/9 - 2/9 ; 
0, 1, (5*exp(-3*t))/12 - (3*exp(t))/4 + 1/3, 2/3 - exp(t)/4 - (5*exp(-3*t))/12 ; 
0, 0, exp(-3*t)/4 + (3*exp(t))/4, exp(t)/4 - exp(-3*t)/4 ; 
0, 0, (3*exp(t))/4 - (3*exp(-3*t))/4, (3*exp(-3*t))/4 + exp(t)/4 ]; 
fplot(PHI,t)

I dont know what you want with the norm function, this norm does not work.