im doing my radar arduino project by using MATLAB and i got an error

clc;
clear all;
close all;

%Customize graph
figure('units','normalized','outerposition',[0 0 1 1]);
whitebg('black');

%Draw Scale Data
th = linspace(0,pi,1000);
R = 10:10:100;  
for i=1:length(R);
    x = R(i)*cos(th);
    y = R(i)*sin(th);
    plot(x,y,'Color', [0.603922 , 0.803922 , 0.196078] ,'LineWidth',1);
    hold on;
end

%Draw Axis data
x0 = [0 100 0 0 0 0 ];  
x1 = [0 100 86.60 50 -50 -86.60]; 
y0 = [0 0 0 0 0 0]; 
y1 = [100 0 50 86.60 86.60 50];
for i=1:length(x0);
    hold on;
    plot([x0(i),x1(i)],[y0(i),y1(i)] ,'Color', [0.603922 , 0.803922 , 0.196078],'LineWidth',2);
end

%Draw Sonar default data
for i=1:180 
    hold on;
    [x, y] = pol2cart(i*0.0174532925, 100);
    h(i) = plot([0,x],[0,y],'g','LineWidth',1);
end

%define serial port
s = serialport("COM5",9600);            

%Draw Sonar Data
while(1)
    data = readline(s);
    [th, r] = strtok(data);
    th = real(str2num(th));
    r = str2num(r);
    set(h(th),'color','r');
    [x0, y0] = pol2cart(th*0.0174532925, 100);
    [x, y] = pol2cart(th*0.0174532925, r);
    set(h(th),'XData',[x0,x]);
    set(h(th),'YData',[y0,y]);
    m = plot([0,x0],[0,y0],'r','LineWidth',3);
    drawnow
    delete(m);
end

im getting error as

Complex values are not supported for 'X'.

set(h(th),'XData',[x0,x]);

[DGM]

Are x0 and x real-valued?

[dpb]

Look like should be, but apparently one or both aren't given the error message.

Set debugger and see what turns one or other to complex.