Want to make linear fitting and plot both graph on the same curve

5 visualizaciones (últimos 30 días)
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
  1 comentario
Daniel Shub
Daniel Shub el 20 de Mzo. de 2013
Editada: Daniel Shub el 20 de Mzo. de 2013
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.

Iniciar sesión para comentar.

Respuesta aceptada

bym
bym el 19 de Mzo. de 2013
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')

Más respuestas (0)

Categorías

Más información sobre Linear and Nonlinear Regression en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

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

Start Hunting!

Translated by