Want to make linear fitting and plot both graph on the same curve
조회 수: 5 (최근 30일)
이전 댓글 표시
I have x, y data
x=[0;0.100000000000000;0.200000000000000;0.300000000000000;0.400000000000000;0.500000000000000;0.600000000000000];
y=[4.67178152947921e-06;4.67353333624452e-06;4.70560728038426e-06;4.74873086195845e-06;4.77333265701103e-06;4.84630647442201e-06;4.87015810633671e-06];
I want to plot x vs y and want to have y-axis in log scale ( NOT log the y data)
this is how I make y -axis with log scale
plot(x,y)
set(gca,'YScale','log')
hold on
Note: x data starts from 0
Now I want to fit a line and show the slope of that curve fitting line + original curve
this is for fitting line.
p=polyfit(x,(y),1);
q=polyval(p,x);
plot(x,q).
It seems to be not right because the fit line isn't straight (it likes power fit or exponential) because it does not start at Initial point . Note log scale ( not log(data))
Please helps. Thanks
댓글 수: 1
Daniel Shub
2013년 3월 20일
편집: Daniel Shub
2013년 3월 20일
This is a duplicate of http://www.mathworks.com/matlabcentral/answers/67684-want-to-fit-linear-curve-on-my-data. Please do not post duplicates, it tends upsets the people who are likely to provide answers.
채택된 답변
bym
2013년 3월 19일
you are going to have to transform your data:
x=[0;0.100000000000000;0.200000000000000;0.300000000000000;0.400000000000000;0.500000000000000;0.600000000000000];
y=[4.67178152947921e-06;4.67353333624452e-06;4.70560728038426e-06;4.74873086195845e-06;4.77333265701103e-06;4.84630647442201e-06;4.87015810633671e-06];
semilogy(x,y,'bo')
c = polyfit(x,log(y),1)
p = polyval(c,x)
hold
semilogy(x,exp(p),'g')
댓글 수: 0
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Linear and Nonlinear Regression에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!