Undefined function 'ln' for input arguments of type 'double'.

I am trying to represent a function and before my code has an operation with a Ln, and when I run the app and click the button give this message 'Undefined function 'ln' for input arguments of type 'double'.' how can i solve it?

P = app.P.Value;

Q = app.Q.Value;

a = app.a.Value;

b = app.b.Value;

Xo = app.Xo.Value;

Yo =app.Yo.Value;

K = b.*Xo-a.*Yo;

C3 = (ln(a.*Yo)-ln(Xo))/- K;

C4 = (ln(b.*Xo)-ln(Yo))/- K;

x = 0:0.2:100;

y3 = K./(exp((K*x-K*C3))-b);

plot (app.Axes,x,y3,'r');

hold (app.Axes,'on')

y4 = - K./(exp(K*x-K*C4)-a);

plot (app.Axes,x,y4,'b');

hold (app.Axes,'off')

Answer 1

[Steven Lord]

The natural logarithm function in MATLAB is named log not ln. There are also log10 and log2 functions listed in the See Also section at the end of the log documentation page.

[Alvaro Mª Zumalacarregui Delgado]

thanks!