how can I fix the code for Segregation Model and population?

I have a code like this:

% model

function schell(grid_size,percent_empty,percent_p1,percent_p2)

grid_size = 50; percent_empty = 30; percent_p1 = 30; percent_p2 = 50;

n = grid_size;

n2 = n^2;

grids = zeros(n); % a grid that occupied by a being from population 1 or 2.

emp = round((percent_empty/100)*n2);

p1 = round((percent_p1/100)*n2);

p2 = round((percent_p2/100)*n2);

tot = emp + p1 + p2;

rand_loc = randperm(n2);

init_emp = rand_loc(1:emp);

init_p1 = rand_loc(emp+1:tot);

init_p2 = rand_loc(tot+1:end);

figure, imagesc(grids);

% frame = getframe;

% writeVideo(writerObj,frame);

but it says "Error using model

Error: File: model.m Line: 1 Column: 10

Class name and filename must match."

How can I fix this? I named this file as "matlab_project".

In this code, I want to include an m * n grid where the "squares" are either unoccupied, or occupied by a being from populations 1 or 2. Initially p1% of the squares are occupied by population 1 occupants, and p2% by population 2, where p1 + p2 < 100. This also have to relate to Segregation Model and population.