Unknown Function (GaussProblemUVF) in VinfVectorFunc.m

[poutasse]

@BrendanLuke15 I am trying to use your repository to generate a Porkchop plot for an Earth-Mars mission. The VinfVectorFunc.m function contains a call to some function called GaussProblemUVF -- [V1,V2,~] = GaussProblemUVF(State1(i,:),State2(i+j-1,:),TOF(j)); -- which is not included in the repository. I assume that this function is used to solve the Lambert problem, so I tried using another published Lambert solver (link), but my plots don't match up with those I've seen you publish on Space Stack Exchange, such as (link). The changes I made to VinfVectorFunc.m to allow for use of (this) Lambert solver are shown below:

function [Vinf1,Vinf2] = VinfVectorFunc(State1,State2,Date1,Date2,TOF,GM_central)
% Function to simplify data generation for interplanetary transfers:
% Inputs:
%   - State1: state vector for departure planet
%   - State2: state vector for arrival planet
%   - Date1: date vector for departure dates
%   - Date2: date vector for arrival dates
%   - TOF: time of flight vector (s)
%   - GM_central: std gravitational parameter of central body (ADDED BY ME)
% Outputs:
%   - Vinf1: vector and magnitude for departure Vinfs
%   - Vinf2: vector and magnitude for arrival Vinfs

Vinf1 = NaN(length(Date1),length(Date2),4);
Vinf2 = NaN(length(Date1),length(Date2),4);

startTime = toc;
for i = 1:length(Date1)
    for j = 1:length(TOF)
        %[V1,V2,~]  = GaussProblemUVF(State1(i,:),State2(i+j-1,:),TOF(j));
        % Modification by me to use a different lambert solver
        TOF_days = TOF/86400;
        [V1,V2,~] = lambert(State1(i,1:3),State2(i+j-1,1:3),TOF_days(j),0,GM_central);
        % X,Y,Z Vinf componenents
        Vinf1(i,i+j-1,1:3) = V1 - State1(i,4:6);
        Vinf2(i,i+j-1,1:3) = V2 - State2(i+j-1,4:6);
        % Vinf magnitude
        Vinf1(i,i+j-1,4) = sqrt(Vinf1(i,i+j-1,1)^2+Vinf1(i,i+j-1,2)^2+Vinf1(i,i+j-1,3)^2);
        Vinf2(i,i+j-1,4) = sqrt(Vinf2(i,i+j-1,1)^2+Vinf2(i,i+j-1,2)^2+Vinf2(i,i+j-1,3)^2);
    end
    % Report Progress:
    % fprintf('Progress:\n %.4f %%\n',i/length(Date1)*100);
    % fprintf('Time Elapsed (mins):\n %.4f \n',(toc-startTime)/60);
    % fprintf('Time Remaining Estimate (mins):\n %.4f \n',(toc-startTime)/(i/length(Date1))/60-(toc-startTime)/60);
    % fprintf('Total Time Estimate (mins):\n %.4f \n',(toc-startTime)/(i/length(Date1))/60);
end

end

I then used the following function call in InterplanetaryTransfers.m:
[VinfA,VinfB] = VinfVectorFunc(Planets.State{i-1},Planets.State{i},Planets.Dates{i-1},Planets.Dates{i},Planets.TOF{i},mu_Sun);
Would you be willing to provide your code for the GaussProblemUVF function or discuss what needs to be modified to make the other solver work? Thank you!