4.2 Whiteboard Coordinate System Error for Function

I am currently going through the Arudino Matlab Engeering Kit, starting with the drawing Robot, and ran into a coding error message that I can not figure out. My code:

function xy = countsToXY(counts,Z_i,Base) % Define constants
    countsPerRadian = countsPerRevolution/(2\*pi);
    r_spool = 0.0045; % Convert counts to angle
    phi = counts/countsPerRadian; % Convert angle to change in string length
    dStringLength = r_spool*phi; % Convert change in string length to change in Z
    dZ = dStringLength/2; %Add change in Z to initial Z to get current Z
    z = Z_i + dz; % Compute x and y from Z1 and Z2
    x = (Base^2 + z(1)^2 - z(2)^2)/(2*Base);
    y = sqrt(z(1)^2-x^2); xy = [x y];
end

But the error that I keep getting is:

Error: File: countsToXY.m Line: 2 Column: 46
Invalid use of operator.

Is there something that I'm missing or was not explained within the lesson that I need to run this code?

Answer 1

[Torsten]

This arithmetic operation is not defined in MATLAB:

2\*pi

[Connor]

How can I make it into an arithmetic operation that is defined

[Torsten]

Depends on what you want to do:

2\pi

ans = 1.5708

2*pi

ans = 6.2832