Making a for loop that appends outputs in a matrix/array

Hello,

I am trying to figure out how to compose a "for" loop that will append outputs at the end of each loop to a matrix. It basically outputs a series of 4 columns by 66049 rows which I want it to do for "k" times. I have kept the parts I am struggling with with capital letter comments.

The three parts I am struggling with are as follows:

1) I need the code to read every 103041 rows of the "sorted" matrix in order to create a different "layer" matrix. So for i=1 it would read from 1:103041, i=2 from 103042:206082 etc.

2) For the expression Zi=Zun(1,1); I need it for i:1 to read the first row of "Zun", then for i:2 to read the second row etc.

3) Finally, at the end of the code the output is a series of 66049 rows by 4 columns of data. I need the code to append each output in the same matrix. As in the next output of the loop for i:2 will go from rows 66050 to 132098 and so on.

I thought about making 33 different matrices (one from each output) and then combining them at the end but this seems counterintuitive.

%Start loop
k=size(Zun,1); %Get number of layers
For i=1:k

%Get one layer of the unique matrix
%Sort everything in a specific array to make the meshgrid afterwards
layer=sorted(1:103041,[1 2 4]); %NEEDS ADJUSTMENT FOR LOOP
x=unique(layer(1:end,1));
tlength=size(x,1);
x=x';
y=unique(layer(1:end,2));
y=y';
t=layer(1:tlength,3);
t=t';
Zi=Zun(i,1); %NEEDS ADJUSTMENT FOR LOOP
%Make a meshgrid from the layer
[X,Y] = meshgrid(x,y);
T=meshgrid(t);
%------------------------------------------
%Create query grid

%Create meshgrid
Xinit = 0:3125:800000;
Yinit = 0:3125:800000;
[Xq,Yq] = meshgrid(Xinit,Yinit);
%Create vector matrix
XY = [Xq(:) Yq(:)];                                     
theta=10; %rotate clockwise by theta
R=[cosd(theta) -sind(theta); sind(theta) cosd(theta)]; %rotation matrix
rotXY=XY*R'; %multiply vector by rotation matrix
Xqr = reshape(rotXY(:,1), size(Xq,1), []);
Yqr = reshape(rotXY(:,2), size(Yq,1), []);
%apply shift
Xqrs = Xqr+175536.2;
Yqrs = Yqr+36617.62772;

%---------------------------------------------------
finalT=interp2(X,Y,T,Xqrs,Yqrs,'spline');
%plot data (I skip this part to keep the message short)
%----------------------------------------------------
%put Xfin,Yfin,Zfin,Tfin into columns
Xfin=reshape(Xq',[],1);
Yfin=reshape(Yq',[],1);
Tfin=reshape(finalT',[],1); 
Zfin=Zi*ones(size(Tfin));
%put X,Y,Z,Tfin in one matrix
Layerout=[Xfin Yfin Zfin Tfin]; %THIS NEEDS TO BE APPENDED EACH TIME 

end 

Thank you for your help,

Pavlos

Answer 1

[James Tursa]

"... I thought about making 33 different matrices (one from each output) and then combining them at the end but this seems counterintuitive..."

That's actually not a bad way to do it at all. Just stuff them into a cell array and then concatenate them all at once at the end.

[Pavlos Farangitakis]

I think that is what I will go with in the end. Any idea how to tackle questions 1 and 2?