How to solve the Gompertz Equation

Hello,

I am trying to solve a regular Gompertz Equation. Very simply... I have put in (and other vital coding information)

%Gompertz Equation

E= -log(r*p)*(p/M)

The system will not generate a map as ln does not read on MATLAB. Any ideas as to how else I should format the equation? Thanks

[Kailin Johnsson]

Correction: This is the equation I was using

%Gompertz Equation

E= -rpln*(p/M)

[Kailin Johnsson]

Update: This equation will generate a graph however, there is no line for the data ran? Is this an error in the code? or of the system?

E= M*(p/M).^exp(-r*t)';

[Star Strider]

See also: How to solve the Gompertz Equation