## How to sort coordinates into a multi dimensional array?

### Abinav Shankar (view profile)

on 30 Sep 2019
Latest activity Answered by Raunak Gupta

### Raunak Gupta (view profile)

on 4 Oct 2019
Hi,
I have three points P1(x1,y1), P2(x2,y2) and P3(x3,y3) and there are 42 values of these points. Through calculation I have individual arrays of x1, x2, y1, y2, x3 and y3. How do I sort them into a multi dimensional array. I want it to be in the form of P = [(x1,y1),(x2,y2),(x3,y3)] and 42 elements in the other dimensions making it a 4D array i.e. 1 Row: 3 Columns: 2 Elements in each column: 42 Layers.

KALYAN ACHARJYA

### KALYAN ACHARJYA (view profile)

on 30 Sep 2019
Can you elaborate more easily (with examples)? Please note that numerical or math is much easier to understand than long text.
Abinav Shankar

### Abinav Shankar (view profile)

on 30 Sep 2019
I have three set of points, P1 with coordinates (x1,y1), P2 with (x2,y2) and P3 with (x3,y3). These three points form a line. I have 42 set of these points i.e. P11,P12, P13,..P142. Similarly 42 set exists for other two points P2 and P3.
From other calculations I have found individual values of x1, x2, y1, y2, x3 and y3. These are in the form of individual row vectors. X1 = [x11, x12, x13,...x142] and Y1 = [y11,y12,y13,...y142]. Similarly, I have row vectors X2, Y2, X3 and Y3 with 42 elements.
I want to sort them in the form of a multi dimensional array P = [(x1,y1),(x2,y2),(x3,y3)]. P has 1 row, 3 columns, 2 elements in each column and 42 pages. So P would be a 1:3:2:42 array. How do I create such an array from my indivdual vectors.

### Raunak Gupta (view profile)

on 4 Oct 2019

Hi,
For creating a 4D array you may use array indexing however for using sort, the dimension on which sorting is needed may be clearly visualized as the structure of array changes after choosing a particular dimension. For creating 4D array so may follow the below example.
X1 = randi(12,1,42); % These are individual row vectors
Y1 = randi(12,1,42);
X2 = randi(12,1,42);
Y2 = randi(12,1,42);
X3 = randi(12,1,42);
Y3 = randi(12,1,42);
Coordinates(1,:,:) = [X1;Y1]; %P1
Coordinates(2,:,:) = [X2;Y2]; %P2
Coordinates(3,:,:) = [X3;Y3]; %P3
final(1,:,:,:) = Coordinates;
% Above final Matrices will be of size 1 x 3 x 2 x 42
If it is required to sort along 2nd dimension with shows P1,P2,P3 then the sort function will compare the values P1,P2,P3 for all corresponding 2 X 42 matrix and will arrange them as required in ascending and descending order. So, the pairing of previous (x11,y11) , (x12,y12) etc. will change. That is why it is recommended to visualize how the sorting is required or what should be the end result.