Plotting non zero elements of an array

I have one array with x-values (X) and y-values (Y) and I want to plot selected lines of those within a loop.

The arrays X and Y have a shape like this:

482.8410  485.8150  487.6960  487.4730  489.4050  491.1900  491.3960  491.8090         0         0
611.4260  612.8240  617.4750  621.8790  622.2030  623.4460  623.0670  622.8820         0         0
355.5830  355.9290  356.7860         0         0         0         0         0         0         0
       0  383.2500  385.3630  387.5590  389.0450  394.2830  396.2180  397.0960  395.4490  395.4630

X and Y have zeros in the same spots, only the non zero values differ. X and Y have a third dim, but for this context only layer 1 is relevant. I want to plot chosen lines individually and only the non zero elements from that line. I use the following plot command:

plot(X(temp,find(X(temp,:,1)>0==1),1),Y(temp,find(Y(temp,:,1)>0==1),1), 'r+', 'MarkerSize', 5, 'LineWidth', 2);

The variable temp is a line vector (i.e. 2 3 4) containing the lines, which are supposed to be plotted. I get the error:

Index in position 2 exceeds array bounds (must not exceed 10).

Error in Bubble_movement_analyser (line 424)

plot(X(temp,find(X(temp,:,1)>0==1),1),Y(temp,find(Y(temp,:,1)>0==1),1), 'r+', 'MarkerSize', 5, 'LineWidth', 2);

Additionally I get the comment, that using logical indexing would improve code perfomance, but I couldn't figure out, how to write that.

Does somebody knows why the Index in position 2 exceeds 10 or how to express this with logical indexing?

Answer 1

[DGM]

Try this instead.

plot(nonzeros(X(temp,:,1)),nonzeros(Y(temp,:,1)), 'r+', 'MarkerSize', 5, 'LineWidth', 2);

[Malte Römer-Stumm]

Hi, that works very well, thank you :)