I am having trouble finding the curve fit of an equation in matlab

26 次查看（过去 30 天）
Duncan Clarke
Duncan Clarke 2020-6-2
评论： Duncan Clarke 2020-6-2
In a homework problem I am doing it asks me to find the curve fit of an equation by linearizing the relationship and then using polyfit to find the constants A and B but the issue I am having is that the equation in question is Axe^(Bx) and the data points are x = [0.1 0.2 0.4 0.6 0.9 1.3 1.5 1.7 1.8] and y = [0.75 1.25 1.45 1.25 0.85 0.55 0.35 0.28 0.18]. The main issue I am having is finding the constants of the equation. I have managed to linearize the equation down to ln(y) = ln(A) + ln(x) + Bx but I don't know how to put that into polyfit to get the constants. Any help would be appreciated.

请先登录，再回答此问题。

采纳的回答

Rik
Rik 2020-6-2
You're almost there:
ln(y) = ln(A) + ln(x) + B*x
ln(y) - ln(x) = ln(A) + B*x
%so:
y2 = ln(y) - ln(x);
p = polyfit(x,y2,1);

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Get Started with Curve Fitting Toolbox 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by