sfit data array output

2 次查看（过去 30 天）
Asliddin Komilov
Asliddin Komilov 2019-9-26
评论： darova 2019-10-7
Hi, I have this:
SS_fit_Xs=fit(Wave_length,real_Solar_spectrum,'poly9');
then I can plot it so easily like this:
plot(SS_fit_Xs,Wave_length,real_Solar_spectrum);
but to get fitted curve as data I have to write down very long formula with 10 coefficients.
Is there any way to do it in a shorter line?
thanks
  1 个评论
Asliddin Komilov
Asliddin Komilov 2019-10-6
now I have this
A=xlsread('ASTMG173.xls');
real_Solar_spectrum=A(:,3);%W/m2
Wave_length=A(:,1)./1e9;% m
SS_fit_Xs=fit(Wave_length,real_Solar_spectrum,'poly9');
SS_fit=SS_fit_Xs(1)*Wave_length.^9+SS_fit_Xs(2)*Wave_length.^8 ...
+SS_fit_Xs(3)*Wave_length.^7+SS_fit_Xs(4)*Wave_length.^6 ...
+SS_fit_Xs(5)*Wave_length.^5+SS_fit_Xs(6)*Wave_length.^4 ...
+SS_fit_Xs(7)*Wave_length.^3+SS_fit_Xs(8)*Wave_length.^2 ...
+SS_fit_Xs(9)*Wave_length+SS_fit_Xs(10);
and SS_fit doesn't look even close to real_Solar_spectrum.
can you help?
thanks

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

darova
darova 2019-10-6
This code
A = xlsread('ASTMG173.xls');
x = A(:,1);
y = A(:,3);
plot(x,y)
Produces
img1.png
Is it the curve you want to approximate?
  2 个评论
Asliddin Komilov
Asliddin Komilov 2019-10-7
编辑：Asliddin Komilov 2019-10-7
yes, but rather x = A(:,1)./1e9, since it makes the difference in fit.
darova
darova 2019-10-7
Is it the way the approximated curve should looks like?
11Untitled.png

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Fit Postprocessing 的更多信息

标签

产品


版本

R2016a

Community Treasure Hunt

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

Start Hunting!

Translated by