How to use if/else on the basis of rows?

I have a pre-specified model that runs smoothly. The problem is that I have two datasets for the same model. The two datasets change just on the basis of the rows:e.g. dataset 1 goes from 1 to 60 and dataset 2 from 61 to 115. All the variables are the same. I would like to avoid computing the same code twice. I'd rather write it nicely and compute it in one shot.

I will give you an example dataset with my model:

data = rand(115,5)

Y_data = data(1:60, :) % dataset 1

Y_data = data(61:115, :) % dataset 2

% This is the model that runs nicely on dataset Y_data. I wanted to avoid to run the model twice,
% first with Y_data from row 1 to 60 and then from row to 61 to 100. I would like to do it in one shot
% the code for the model is fully automated so it's just a matter of making it work first on dataset 1 and then
% on dataset 2 in one unique code

T = size(Y_data,1);
P  = 3; % number of lags used in LP for controls

H_min = 1; 
H_max = 25; 

y  = Y_data(:,1); % endogenous variable
x  = Y_data(:,2); % shock 
w  = lagmatrix(Y_data(:,[3:5]), 1:P ); 
newData = cat(2, y, x, w)

% Remove missings from data
newData(any(isnan(newData), 2), :) = [];

% Re-declare variables after removing missings
y  = newData(:,1); % endogenous variable
x  = newData(:,2); % shock
w = newData(:,3:size(newData,2)); % control variables and lags

r = 3; 
lambda = 10000; 

slp    = locproj(y,x,w,H_min,H_max,'smooth',r,lambda); 

%% Cross-Validation Choice of Lambda

slp = locproj(y,x,w,H_min,H_max,'smooth',r,0.01);

lambda = [1:10:1000] * T;
slp    = locproj_cv(slp,5,lambda);
lambda_opt = lambda( min( slp.rss ) == slp.rss );

%% Confidence Intervals

r      = 3;
slp    = locproj(y,x,w,H_min,H_max,'smooth',r,lambda_opt); 
slp    = locproj_conf(slp,H_max,lambda_opt/2);

What I thought it could sort this out was using if/else, something like:

% This is wrong but it gives you an idea of what I was trying to do and get
% trying to tell MATLAB, fun the code first from dataset 1 (row 1:60) and then the same on dataset 2 (from row 61:115)

if  Y_data = data(1:60, :);
    
else
       Y_data = data(61:115, :);
end

% model code as above just here - not to make it too long

% the output therefore should save both results for dataset1 and dataset2

I got stuck and don't manage to go ahead. Can anyone help me? It would make my day.

Thank you very much!

[Mohammad Sami]

Write your code as function and then you can call it with any data you want.

if true
  Out1 = myfunction(ydata(1:60,:));
  Out2 = myfunction(ydata(61:end,:));
end

[Armando MAROZZI]

Thanks a lot! Super helpful!

Answer 1

[David Hill]

m=[1,60,61,115]
for k=1:2:3
    Y_data=data(m(k):m(k+1),:);
    %everything else the same
end

[Armando MAROZZI]

Thanks a lot David! Super helpful!