Multiple y plots on same logarithmic scale for the x-axis

0
votes

I am trying to plot 3 curves using the semilogx matlab function and add a fourth line to an additional y axis on the right. All of them should be plotted on the same logarithmic scale for the x-axis. The following code indicates the derived error; the x-axis is incorrect. The figure has to have a single x-axis mode of ticks, the logarithm one. How could this be fixed?

Plus, how can I add a legend for these 4 curves?

close all, clc
figure, semilogx([1:100:1000],[rand(1,10)],'bo-'), 
xlabel('xlabel'),ylabel('ylabel'), hold on; 
semilogx([1:100:1000], [rand(1,10)], 'ro-'), hold on,
semilogx([1:100:1000], [rand(1,10)], 'ko-'), hold off
legend('1','2','3','Location','Best')

ax1 = gca;
ax2 = axes('YAxisLocation','right',...
           'Color' , 'none',...
           'YColor', 'm');
linkaxes([ax1 ax2 ], 'x')

x4 = [1:100:1000];
y4 = [rand(1,10)*2];
line(x4, y4, 'color', 'm', 'Marker','x','LineStyle',':', 'parent',ax1)
ylabel('y2')
1
matlabplot

1 Answers

1
votes

You can use plotyy function to plot two of your lines, one on the right and one on the left. You can then hold on and plot the remaining lines using semilogx.

plotyy([1:100:1000], [rand(1,10)], [1:100:1000], [rand(1,10)]*2, @semilogx);
hold on;
semilogx([1:100:1000], [rand(1,10)], 'ro-');
semilogx([1:100:1000], [rand(1,10)], 'mo-');
hold off;
legend('Line1','Line2','Line3','Line4','Location','Northwest')

enter image description here