Undefined function error message

Hi guys, I am using Live Editor and I want to write a function and then have that function automatically be called when I hit run all. Before having the function automatically be called when I run the script, I have tried to just call the function from the command window, but it does not work. It says that the function is undefined.

Here is my code:

 clear all;

 function myfun(initialspeed, initialangle, Nmaxstep)

 %Fundamental Constants
 m_e = 9.10938188E-31; %Mass of positron
 q_e = 1.60217646E-19; %Charge of positron
 qbym = q_e/m_e; %Charge to mass ration of positron

 %Input Fields
 Ey = 10E5 %Y component of electric field
 Ex = 0 %X component of electrin field
 Bz = 1  %Z component of magnetic field

 %Initial conditions
 x1 = 0; y1 = 0; %having electron start at the origin for simplicity
 r1 = [x1,y1] %initial position vector of electron
 theta1 = initialangle*pi/180; % converting the direction from degrees 
 to radians
 v1 = [initialspeed*cos(theta1), initialspeed*sin(theta1)] % initial 
 velocity
 r = r1; v = v1;

 %Time step for loop
 deltat = (qbym*Bz)^-1/1000; %qbym*Bz is the cyclotron frequency

 %Loop to calculate trajectory
 for istep=1:Nmaxstep

     %Current position
     xorbit(istep)=r(1);
     yorbit(istep) = r(2);
     t=(istep-1)*deltat;

     %acceleration at this position
     accel(1)=qbym*(Ex+v(2)*Bz);
     accel(2)=qbym*(Ey-v(1)*Bz);

     %using Euler's method to calculate new state
     r = r + v*deltat;
     v = v + accel*deltat;
 end

 %Plotting trajectory
 clf; figure(gcf);
 plot(xorbit,yorbit);
 title('Positron trajectory')
 xlabel('X (meters)')
 ylabel('Y (meters)')
 end  
 end

When I try to call my function myfun(#,#,#), I get an error saying that the function is undefined. Why is this not working?

Answer 1

[Walter Roberson]

When you define a function within a script, the function cannot be called from outside the script.

When you define a function inside a script, you should imagine that at the top of the script you had put in "function" with the name of your file, at least for the purposes of locating routines.

... But putting a "clear all" in a script is not a good idea: it tells MATLAB to scrub everything except existing graphics objects. "clear all" could, in theory, even cause MATLAB to lose track of which script or function it was executing, because "clear all" is the programming equivalent of Wile E. Coyote blowing up the piece of rock he is standing on.

[Salvatore Pace]

Thank you very much!