Creating a scatter plot with smooth lines and markers?
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Hello, I am trying to create a scatter plot with smooth lines and markers in Matlab, as I can do easily in Excel. I do not think there is a way to use the scatter command to do this, so I'm asking if there is another way to plot the data in the same way (scatter format) but with smooth lines and markers? Thank you.
Ashley
4 Comments
Chetan Rawal
on 18 Dec 2014
I am not quite sure what you mean by a line connecting all points. Scatter diagram by definition places points on the plot.
1) If you are looking for a line connecting the points, use the plot command instead
>>plot(x,y,'-o')
2) If you want a smooth line that best fits through all your points (but not necessarily passes through them), then you need to do curve fitting . If you want a smooth line passing through all points, try using splines .
Accepted Answer
Chad Greene
on 18 Dec 2014
Edited: Chad Greene
on 18 Dec 2014
You can plot the line with plot(x,y,'-',lineproperty,linevalue) then use hold on and plot markers of the same data with plot(x,y,'x',markerproperty,markervalue) or you can combine them into one command like this:
plot((1:5).^2,'o-','linewidth',3,'markersize',40,'markerfacecolor','g')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/177204/image.png)
4 Comments
Chad Greene
on 19 Dec 2014
I suspect something in your data set is out of order.
indep = 1:.1:10;
dep = sin(indep)+rand(size(indep));
plot(dep,indep,'ro-')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/180656/image.png)
looks good. Then get the data out of order:
rp = randperm(91);
plot(dep(rp),indep(rp),'ro-')
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/180657/image.png)
More Answers (2)
Scott Webster
on 18 Dec 2014
You can use both the scatter and line commands like this...
x = [1 2 3]
y = [1 3 9]
scatter(x,y)
hold on
line(x,y)
xlim([0 4])
ylim([0 10])
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/177206/image.png)
2 Comments
Scott Webster
on 19 Dec 2014
Sounds like maybe you are not sorting correctly. Anyway, here are three examples in case it helps:
%%plot 1
figure
x = [1 2 3 1.5];
y = [1 4 9 5];
scatter(x,y)
hold on
line(x,y)
xlim([0 4])
ylim([0 10])
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/180653/image.png)
%%plot 2
figure
sorted=sortrows([x' y']);
sorted_x = sorted(:,1);
sorted_y = sorted(:,2);
scatter(sorted_x,sorted_y)
hold on
line(sorted_x,sorted_y)
xlim([0 4])
ylim([0 10])
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/180654/image.png)
%%plot 3
figure
fitx=linspace(0,4,100);
fity = interp1(sorted_x,sorted_y,fitx,'spline');
scatter(sorted_x,sorted_y)
hold on
line(fitx,fity)
xlim([0 4])
ylim([0 10])
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/180655/image.png)
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