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

4 Ansichten (letzte 30 Tage)
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 Kommentar
Daniel Shub
Daniel Shub am 20 Mär. 2013
Bearbeitet: Daniel Shub am 20 Mär. 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.

Melden Sie sich an, um zu kommentieren.

Akzeptierte Antwort

bym
bym am 19 Mär. 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')

Weitere Antworten (0)

Community Treasure Hunt

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

Start Hunting!

Translated by