Jorge Leiva

15 Reputation

2 Badges

13 years, 134 days

MaplePrimes Activity


These are replies submitted by Jorge Leiva

I think if you check types (using whattype command) is possible to understand the problem with the first code.
 
> restart;
> pwl := x < 0, -1, x < 1, 0, 1;
x < 0, -1, x < 1, 0, 1
> whattype(pwl);
exprseq
> k := proc (x) options operator, arrow; piecewise(pwl) end proc;
x -> piecewise(pwl)
> whattype(k);
symbol
> k;
k
> whattype(k(x));
function
> k(x);
piecewise(x < 0, -1, x < 1, 0, 1)
 
k is an operator and you need an expression for plot.
I hope it's help.
 
Regards.
I think if you check types (using whattype command) is possible to understand the problem with the first code.
 
> restart;
> pwl := x < 0, -1, x < 1, 0, 1;
x < 0, -1, x < 1, 0, 1
> whattype(pwl);
exprseq
> k := proc (x) options operator, arrow; piecewise(pwl) end proc;
x -> piecewise(pwl)
> whattype(k);
symbol
> k;
k
> whattype(k(x));
function
> k(x);
piecewise(x < 0, -1, x < 1, 0, 1)
 
k is an operator and you need an expression for plot.
I hope it's help.
 
Regards.

 

 

The problem with your approach is that you have an infinite number of curves that accomplished your constraints:

f(8)=g(8) and diff(f,x)(8)=diff(g,x)(8).

With the approach I described before I get the following graph for f and g;
 

 

 

The problem with your approach is that you have an infinite number of curves that accomplished your constraints:

f(8)=g(8) and diff(f,x)(8)=diff(g,x)(8).

With the approach I described before I get the following graph for f and g;
 

What do you understand by "get a graph like" ?

I understood try to find a and b such that the "distance" between g = 0.00083*x^4-0.09375*x^2+3 and f = a*cos(b*x)+3 is a global minimum in the interval x =[-8..8]

Using a "distance" based in the L2 norm:

distance = int((f-g)²,x=-8..8)

you could try to find an answer (maybe using the optimization package).

I suggest to try with a more general f = a*cos(b*x)+c. You will get a best solution.

 

What do you understand by "get a graph like" ?

I understood try to find a and b such that the "distance" between g = 0.00083*x^4-0.09375*x^2+3 and f = a*cos(b*x)+3 is a global minimum in the interval x =[-8..8]

Using a "distance" based in the L2 norm:

distance = int((f-g)²,x=-8..8)

you could try to find an answer (maybe using the optimization package).

I suggest to try with a more general f = a*cos(b*x)+c. You will get a best solution.

 

Page 1 of 1