MATLAB: Can any one explain this line of the code.

summation

Data=[-1 -0.5 1 2; -4 -3 2 3];
m=2.5; % slope is kept constant
c=-10:0.1:10; % different values for intercept c to plot the cost
Cost=zeros(1,length(c));
for i=1:length(c)
Cost(i)=(1/4)*sum( (Data(2,:)'-(m*Data(1,:)'+c(i))).^2);
end
The line in side for loop.
Data(2,:)=[ -4,-3 2 3]'
m*Data(1,:)=2.5*[-1 -0.5 1 2]'
c(1)=-10
How can we add m*Data(1,:)+(-10)

Best Answer

Per matrix math rules, when you add a single value to a matrix, that operation is applied to all values of the matrix individually.
>> Data(1,:)
-1 -0.5 1 2
>> m*Data(1,:)
-2.5 -1.25 2.5 5
>> m*Data(1,:)
-12.5 -11.25 -7.5 -5