How to plot with 3 matrix

Hi everyone,

I used "plot" for drawing 2 two curve in one plot. I got it but one from these (red line) is not beautiful (the curve is not smooth) and I didn't understand why in area legend's didn't show green line. Anyone help me please. Below show the code I did. Thank you for advance.

clear all;
clc;
hold on
kr=[0 10 20 30 40 50 60 70 80 90];
M1=[0    0.2757    0.4979    0.4989    0.4481    0.3644    0.2910    0.2228    0.1380    0.0346];
M2=[0    0.0241    0.0916    0.1786    0.2613    0.3322    0.3895    0.4343    0.4658    0.4809];
 plot(kr,M1,'x',0:90, interp1(kr,M1,[0:90],'spline'),'r','linewidth',1.5);
 plot(kr,M2,'x',0:90, interp1(kr,M2,[0:90],'spline'),'g','linewidth',1.5); 
  grid on 
  xlabel('heel angel')
  ylabel('arm')
  legend('ld','ls','Location','northwest')
  title('Diagram stability')

Answer 1

[Star Strider]

If you want the red and green lines to show, you need to plot them separately, and create handles for them to pass to the legend call:

hold on
kr=[0 10 20 30 40 50 60 70 80 90];
M1=[0    0.2757    0.4979    0.4989    0.4481    0.3644    0.2910    0.2228    0.1380    0.0346];
M2=[0    0.0241    0.0916    0.1786    0.2613    0.3322    0.3895    0.4343    0.4658    0.4809];
plot(kr,M1,'x')
hp1 = plot(0:90, interp1(kr,M1,[0:90],'spline'),'r','linewidth',1.5);
plot(kr,M2,'x')
hp2 = plot(0:90, interp1(kr,M2,[0:90],'spline'),'g','linewidth',1.5); 
grid on
xlabel('heel angel')
ylabel('arm')
legend([hp1 hp2], 'ld','ls','Location','northwest')
title('Diagram stability')

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[Mi Tung]

Thank you very much. So could you make the line curve is more smooth?

[Star Strider]

My pleasure!

It looks very smooth to me already. I do not know what ‘more smooth’ means to you, so I defer to you to experiment with it. One option is to use 'pchip' (my usual preference) or 'makima' rather than 'spline'. The 'makima' method appears to me to work best here, however that is your decision.

If my Answer helped you solve your problem, please Accept it!

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