Timeline for Non-linear regression simulation
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 25, 2023 at 19:21 | comment | added | yixjia |
@Bill Thank you for your explanation! The value is good enough. If we express Exp[-1.8664 + 0.376405t] - x3 in the form of x1 Exp[x2 t] - x3, we can obtain x1≈0.15; x2≈0.37; x3≈1.1;
|
|
| Mar 25, 2023 at 19:16 | comment | added | JimB |
What is the definition of CR ?
|
|
| Mar 25, 2023 at 19:06 | comment | added | Bill |
@yixjia Everyone wants Mathematica to be FAST! So Mathematica remembers x=0.2 and will use that each time you enter x again. And it does this for bigger expressions. You can tell Mathematica to forget by doing x=.; or by restarting Mathematica or by looking up how to use Clear or ClearAll Different subject. The value for b I found was not near 1.1. Is the value I found good? Or should the calculation be different to get closer to 1.1? Note in Mathematica Log is "natural log"
|
|
| Mar 25, 2023 at 19:02 | comment | added | yixjia | Oh, I guess the problem is with my edition of Mathematica. When I tried it online, it worked. Thank you! | |
| Mar 25, 2023 at 18:47 | comment | added | Ulrich Neumann | @yixjia Restart your kernel and try again! | |
| Mar 25, 2023 at 18:46 | comment | added | yixjia |
Thank you so much! However, when I wrote sol = FindFit[logdata, m*x + b, {m, b}, x];, it didn't work and gave me an error message saying that 0.2 is not a valid variable. I'm also confused about why 0.2 is showing up.
|
|
| Mar 25, 2023 at 18:20 | comment | added | Bill |
Try this logdata=Map[{#[[1]],Log[#[[2]]]}&,data]; sol=FindFit[logdata,m*x+b,{m,b},x]; ef=E^(m*x+b)/.sol; Show[ListPlot[data],Plot[ef,{x,20,29}]] and see how close that is to what you want. If it isn't right then please explain what I've misunderstood and need to change.
|
|
| Mar 25, 2023 at 18:14 | history | edited | yixjia | CC BY-SA 4.0 |
added 47 characters in body
|
| Mar 25, 2023 at 17:59 | history | asked | yixjia | CC BY-SA 4.0 |