How can one, out of several xlines in a script be ignored when the x-input value is missing?

I have several datasets stored as different workspaces. I need to plot these data and mark specific timepoints of blood sampling with an xline. Since there are many plots to be done, I have tried to automate this by using a script in which I only have to note the time that is to be highlighted.

My problem is, for different plots different data samplings is missing. For example:

x = linspace(0,100,10)
y = randi([0 10],1,10)

plot(x,y)

a = input('1:')
b = input('2:')
c = input('3:')

xline(a,'-k')
xline(b,'-r')
xline(c,'-b')

If one of the three timepoints ("1-3") is missing, I want to skip that entry by pressing 'Enter'. How can I get the script not to execute/draw the xline with the missing x-value (or empty array [ ] that is created with the blank input)?

Thank you in advance!

Answer 1

[Adam Danz]

You can plot all lines at the same time, skipping empty values. Then you can set the colors of the line.

a = input('1: ');
b = input('2: ');
c = input('3: ');

xlh = arrayfun(@(x)xline(x,'-'),[a,b,c]); 
colors = {'k','r','b'}; 
set(xlh, {'color'}, colors(~cellfun(@isempty,{a,b,c}))')

*This solution was updated after realizing that xline() does not accept NaN values.

[Erik Näslund]

Thank you for answer, but I recive the following error when leaving one blank input:

Error using xline (line 29)
NaN is not a valid Value.

Is there a way of using Decision Branching to omit drawing the xline with the blank input?

[Adam Danz]

Sorry about that; I find it odd that matlab doesn't just ignore the NaN values in xline() as they do in other plotting functions.

I updated my solution with the fix.

[Erik Näslund]

Thank you very much! This works fine.

[Adam Danz]

Glad I could help!