plot not saveable, if it displays multiple functions

Hey there,

I am relatively new to Matlab and would greatly appreciate your help!

I am trying to save a plot of data I have collected (I have added an example of my script below). This works if I only plot one string of data, but as soon as I add a second one, the error

Conversion to matlab.graphics.chart.primitive.Line from cell is not possible.

Error in saveas (line 75)
                h(n) = hP;

appears. Do I need to somehow configurate the plot, so that it is saveable?

My script:

%%load stored data 
matfile1 = 'filedirectory1';  
load(matfile1);  
x1 = X;  
y1 = Y;  
matfile2 = 'filedirectory2';  
load(matfile2);  
x2 = X;  
y2 = Y;

%%create Multiplot  
image = plot(x1,y1,'b.',x2,y2,'r.');  
%%save plot  
saveas(image, 'filedirectory/image.png', 'png' );

Answer 1

[Jan]

plot replies the handles of the line object, but saveas needs the handle of the figure:

FigH = figure;  % Before the code
...
saveas(FigH, 'filedirectory/image.png', 'png' );

Answer 2

[Guillaume]

image = plot(...

plot does not return an image so your variable name is very misleading. It returns Line objects. I'm suprised that saveas works when you pass it a scalar Line object. Clearly it doesn't work with an array of Line objects but it shouldn't even work with a scalar. saveas expects a figure handle.

saveas(gcf, 'filedirectory/image.png', 'png' );

And for clarity you should change the plot line to:

hline = plot(...

although since you don't use the output, you could dispence with the variable altogether.

Answer 3

[Larissa Billig]

Thanks for your help!