Converting equation to matlab

Hi, I am trying to convert the following equation to matlab code. I have a bunch of defined constants above this code but I am trying to figure out if my formatting is correct since I keep getting the wrong answer. I need to multiply the two functions and they are dependant on the variable E, everything else is a constant. Thanks!

[David Hill]

Is E a row vector and all others are scalar?

[Christos Papedo]

Yes exactly. Here are my variable definitions. My N matrix should be in the order of 10^21 but I am getting 10^-12

clear, clc;

m = 9.11*10^(-31);

h = (6.63/(2*pi))*10^(-34)*(6.242*10^18); % corrected to change J to eV

q = 1.6*10^(-19);

k = 1.38*10^(-23)*(6.242*10^18); % corrected to change J to eV

T = 300;

Ef = 0; %Assuming fermi level is at 0

Ec = Ef + .55;

E = Ec:.001:Ec +.3;

g = (1/(2*(pi^2)*(h^3)))*((2*m)^(3/2))*(sqrt(E-Ec));

f = 1./(1+exp((E-Ef)./(k*T)));

N = g.*f;

[Jon]

For the future, it is good to use the insert code button on the Answers toolbar to insert code rather than using a screen shot. Then people can easily copy and paste from there to try your code without having to retype it.

[madhan ravi]

Always post the code, don’t let others type the same code.

Answer 1

[Jon]

% note .* to get element by element multiplication
% ./ for element by element division
g = 1.0/(2*pi^2*h^3)*(2*m)^(3/2)*sqrt(E-Ec) 
f = 1.0 ./(1+exp((E-Ef)/(k*T))) 
N = g.*f 

Sorry I didn't notice you already had some code for N = g.*f at the bottom of your original post, I just saw the typeset equations. Maybe this is equivalent what you already have. If so I guess there is a problem in your definition of the constants. In any case you have some unecessary parenthesis and also the ./ in your first equation is not needed when the denominator is a scalar.

You also have some apparently unecessary parentheses in your definition of the constants. This is a good reference on Matlab's precedence rules https://www.mathworks.com/help/matlab/matlab_prog/operator-precedence.html

[Christos Papedo]

Thank you very much.

Answer 2

[SUFIZATUL AIN MAMAT]

f\left(x\right)=-3x^3+5x^2+14x-16