Show only two y values in a plot

Hello all,

Any possible way to show only two value (0.02 and 0.04) for the y-axis, because the other values are just noise.

This is what I use for now to plot:

 figure()
    plot(time,wavelength,'b-x', 'LineWidth',2)
    grid
    axis tight
    xlabel('Time')
    ylabel('Wavelength')
    hold on

Thank you!

[Dyuman Joshi]

Try

idx=ismember(wavelength,[0.02 0.04]);
%ideally one should use ismembertol
plot(time(idx),wavelength(idx),'b-x', 'LineWidth',2)

[Hussein Kokash]

Thank you so much! Dyuman Joshi, it works flawlessly!

[Hussein Kokash]

Hello Dyuman Joshi,

Any idea why it is not showing values such as 0.033333333333333 but works well with values such as 0.2 or 0.04, etc?

Thanks!

[Dyuman Joshi]

Because the code I wrote only checks for 0.02 and 0.04, which is what you wanted.

[Hussein Kokash]

What I meant that we changing the values to 0.033333333333333 it doesn't show up:

figure(6)

idx=ismember(wavelength,[0.033333333333333, 0.2]);

%ideally one should use ismembertol

plot(time(idx),wavelength(idx),'b-x', 'LineWidth',2)

hold on

This is what is plotted:

Thanks!

[Dyuman Joshi]

This is the problem with floating point numbers, which is why I made the comment.

Try -

 idx=ismembertol(wavelength,[0.033333333333333, 0.2],1e-15);

There's still a chance that it might not work, because I don't know the values. If it doesn't, post your data here. Only then can I can say for sure, what you can do.

[Hussein Kokash]

Should have posted it earlier, my mistake, here they are:

0.0200000000000000

0.0200000000000000

0.0400000000000000

0.0400000000000000

0.0200000000000000

0.0200000000000000

0.0200000000000000

0.0400000000000000

0.0200000000000000

0.0400000000000000

0.0400000000000000

0.00833333333333333

0.0133333333333333

0.00869565217391304

0.00869565217391304

0.00869565217391304

0.00833333333333333

0.0142857142857143

0.0153846153846154

0.0153846153846154

0.00714285714285714

0.0333333333333333

0.0200000000000000

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.0333333333333333

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.0500000000000000

0.100000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.0333333333333333

0.200000000000000

0.200000000000000

0.0666666666666667

0.200000000000000

0.100000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.0666666666666667

0.100000000000000

0.0666666666666667

0.0666666666666667

0.200000000000000

0.200000000000000

0.0500000000000000

0.0666666666666667

0.0666666666666667

0.200000000000000

0.200000000000000

0.0400000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.0400000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.0400000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.100000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.100000000000000

0.0666666666666667

0.100000000000000

0.200000000000000

0.100000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.100000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.200000000000000

0.0666666666666667

0.0666666666666667

0.100000000000000

0.100000000000000

Thanks again, appreciate it.

[Dyuman Joshi]

Alright, did my code work? the one with ismembertol() ?

[Hussein Kokash]

Hello Dyuman Joshi,

I changed the 1e-15 to 1e-10 in idx=ismembertol(wavelength,[0.033333333333333, 0.2],1e-15); and now it is working.

Thank you so much! and sorry for the trouble!

Have a great day!

Answer 1

[KSSV]

tol = 10^-3 ;   % fix your tolerance 
idx = abs(wavelength-0.02)<=tol | abs(wavelength-0.04)<=tol ;
plot(time(idx),wavelength(idx),'+r')