# how to plot smooth line plot?

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Vishnu Dhakad on 5 Feb 2020
Commented: Vishnu Dhakad on 7 Feb 2020
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.

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Vishnu Dhakad on 5 Feb 2020
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 on 5 Feb 2020
If you want a smooth line in the loglog domain, you should interpolate in that domain as well.
Vishnu Dhakad on 5 Feb 2020
how to do?

Hiro Yoshino on 5 Feb 2020
How about increasing the number of data by using interpolation?:

Rik on 5 Feb 2020
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
hold off

Vishnu Dhakad on 6 Feb 2020
I am tried above code and got a plot(Figure04).
But I want plot like Figure02(which is genereted by excel).
Thanks again
Rik on 6 Feb 2020
I didn't use your data, but generated some random data. Did you try using your data and my code?
Vishnu Dhakad on 7 Feb 2020
Yes, I have used your code.

R2019b

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