estimate the parameters of an equation
    2 visualizzazioni (ultimi 30 giorni)
  
       Mostra commenti meno recenti
    
    Nikolas Spiliopoulos
 il 20 Mar 2017
  
    
    
    
    
    Risposto: Steven Lord
    
      
 il 20 Mar 2017
            Hi there,
I have a question:
I have an equation like this: 45=a*5^b;
is there any way to estimate a and b only from this equation?
thanks
1 Commento
  Adam
      
      
 il 20 Mar 2017
				At a glance, without putting much thought into it I'd imagine there are an infinite number of solutions unless you are restricting yourself to integers only.
Risposta accettata
  Star Strider
      
      
 il 20 Mar 2017
        No.
You are estimating 2 parameters with 1 (x,y) data pair. There is no unique solution.
0 Commenti
Più risposte (1)
  Steven Lord
    
      
 il 20 Mar 2017
        Borrowing a problem from Cleve: "I'm thinking of two numbers. Their average is 3. What are the numbers?" I just wrote down my answer; I would be very surprised if you gave the same answer I wrote down.
Like Cleve's question, your question has infinitely many solutions. But if you want the solution for a in terms of b:
syms a b
f = 45 == a*5^b;
asol = solve(f, a)
check = isAlways(subs(f, a, asol))
0 Commenti
Vedere anche
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!