how to plot smooth line plot?

I have data in x,y.

I have plotted x,y in log scale in both axises

but I did not getting smooth plot.

How to get it like excel plot.

please find the attached data and pics of the plot

Figure01 from MATLAB

Figure02 from Excel

I dont have signal processing tool.

[Rik]

Have you tried spline interpolation?

[Vishnu Dhakad]

Yes

I used following code but I did not get plot like figure02

>> xq = (0.25:0.001:32);

>> V = interp1(X, Y1, xq, 'spline');

>> hold on

>> loglog(xq,V,'r')

[Rik]

If you want a smooth line in the loglog domain, you should interpolate in that domain as well.

[Vishnu Dhakad]

thanks for your suggetion

how to do?

Answer 1

[Hiro Yoshino]

How about increasing the number of data by using interpolation?:

https://jp.mathworks.com/help/matlab/ref/interp1.html?s_tid=doc_ta

Answer 2

[Rik]

The code below generates some example data and then interpolates the data in the loglog domain.

%generate some example data
X=exp(linspace(log(0.25),log(32),40));
Y1=randi([15 25],1,numel(X)).*exp(X./15);


xq = (0.25:0.001:32);
V = exp(interp1(log(X), log(Y1), log(xq), 'spline'));
figure(1),clf(1)
loglog(X,Y1,'.b')%plot orignal data
hold on
loglog(xq,V,'r')%add interpolation
hold off

[Vishnu Dhakad]

Thanks for your answer

I am tried above code and got a plot(Figure04).

But I want plot like Figure02(which is genereted by excel).

Thanks again

[Rik]

I didn't use your data, but generated some random data. Did you try using your data and my code?

[Vishnu Dhakad]

Yes, I have used your code.