Plotting multiple vertical lines with a for loop

I need to plot vertical lines on a graph at points defined from an array imported from an excel file.

Samples = xlsread('ProjectData.xlsx','Sampling Strategy','A6:B44');
SampleDepth = Samples(:,2);

for i = 1:SampleDepth
    
xline(i);

end 

SampleDepth is a 29x1 double. I need it to plot a vertical line (hence using xline) for each depth specified. I thought that using a for Loop like this would therefore plot a vertical line at each specified point, but Matlab returns:

Error using xline (line 29)
Must pass in a value.

Error in IsotopeGraphs (line 24)
xline()

What needs to be done to fix this? Can xline even be used like this or does it not work?

[KSSV]

You cannot draw a line with single point..you need to have two points...read the documentation.

what is xline by the way?

[Cian McAuley]

You do not need two points to draw a line if you use the function xline() or yline(), which will draw a straight line perpendicular to that axis at the specified point.

Answer 1

[Ameer Hamza]

You seem to have a function named xline() which is shadowing the built-in function xline(). Check the output of

which xline

and if it is not something like

.../toolbox/matlab/specgraph/xline.m

then change its name to something else.

Answer 2

[Chenguang Yan]

Try this

sz = size(SampleDepth,1);  
for i = 1:sz
xline(SampleDepth(i));
end

Answer 3

[Andy]

SampleDepth is a matrix so cannot be used to generate the for loop.

I think you meant to use the length of SampleDepth

for i = 1:length(SampleDepth)