You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: GM_PHD_Predict_Birth.m
    path of file: ./repos/GM_PHD_Filter
    
    the code of the file until where you have to start completion: %GM_PHD_Predict_Birth
%Matlab code by Bryan Clark
    
function will give it a higher starting weight.

%The means of these will be the position in Cartesian space where they are detected
%The covariances & weights are calculated according to Vo&Ma
s = sprintf('Step 1: Prediction for birthed and spawned targets.');
disp(s);

m_birth_before_prediction = [m_birth, m_spawn]; %Need to store these BEFORE prediction for use in the update step.

%Perform prediction for birthed targets using birthed velocities.
for j = 1:numBirthedTargets
    i = i + 1;
    %w_birth was already instantiated in GM_PHD_Create_Birth
    m_birth(:,j) = F * m_birth(:,j);
    P_range = calculateDataRange4(j); 
    P_birth(:,P_range) = Q + F * P_birth(:,P_range) * F';
end