# Use Matlab Function Block to plot into figure created by Matlab Script

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Jannis on 6 Nov 2022
Commented: Jannis on 15 Nov 2022
Hello,
my plan is to create a figure with a Matlab script and then plot the results from my Simlink Simulation in this specific plot, using a Matlab function block.
Here is the script where the figure to plot the results is created:
ax1 = axes;
imshow(map_scales, 'Parent',ax1)
hold on
My original idea was to use the ax1 in the matlab function block to plot the results in this figure. But this does not seem to work:
Here is a picture of the maltabl function block and the code inside it:
function path_plotting(x_pos, x_pos_prev, y_pos, y_pos_prev)
x_coodinates = [x_pos_prev, x_pos];
y_coodinates = [y_pos_prev, y_pos];
plot(x_coodinates, y_coodinates, 'LineWidth', 2, 'Color', 'b', 'Parent', ax1)
end
Does anyone have an idea how to solve this?

Simon Chan on 6 Nov 2022
Try this in the function path_plotting
function path_plotting(x_pos, x_pos_prev, y_pos, y_pos_prev, ax1)
x_coodinates = [x_pos_prev, x_pos];
y_coodinates = [y_pos_prev, y_pos];
plot(ax1,x_coodinates, y_coodinates, 'LineWidth', 2, 'Color', 'b')
end
Jannis on 6 Nov 2022
HI, thanks for you answer, but this does not seem to work. I think there might be no solution for my problem because simulink does not support the data type of an axes vairable.
I changed ax1 to a parameter data type and I received this error
See screenshot below

Paul on 13 Nov 2022
Edited: Paul on 13 Nov 2022
Hi Jannis,
I got this model to work
The code in the Matlab Function block is
function y = fcn(u,t)
persistent ax1
if isempty(ax1)
ax1 = gca;
end
plot(ax1,t,u,'r.')
y = u;
end
In your use case, maybe you can replace the ax1 = gca; with either your code, or a function that runs your code to create the image and return the axis handle. Anyway, I think that whatever you're trying to do is feasible.
##### 2 CommentsShowHide 1 older comment
Jannis on 15 Nov 2022
Thank you very much this solves my problem

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