Compare values in array1 with array2 and store a new value in a new array if match found

I have a problem of comparing two arrays on Matlab scripting and below I have explained.

%Array1 has one column

Array1=[1.56357468109619
1.61046126078761
1.81562025010618
1.68554263182706
2.01705143067582
2.20087755213663
1.90411420706440
1.86094752726691
1.92177045043986
1.78486562784988
1.85660250759791
1.53693897473804
2.01744530015071
1.90897780937155]

%Array2 has two columns

Array2=
2.02888000000000         600;
1.80918000000000  500;
1.65728000000000  400;
1.52849000000000  300;
1.35517000000000  200;
1.13304000000000  100;
1.00398000000000  0

I want to compare each value of the single column in Array1 with the values in column 1 of Array2. If the value of Array1 matches or fits within a range or within a given limit range with a value in column1 of Array2, I wish to create a new array (Array3) with the corresponding value in Column2 of Array2.

Example: 1st value in column1 of Array1 = 1.61046126078761 Since this value is closest to 3rd value of column1 in Array2, I want to assign the first value in Array3 as 400. Likewise I want to check all the values in Array1 and assign the values and create the new Array3

Would be great if someone could help me out! Thanks in advance!

Best wishes Sarala

[Stephen23]

"Example: 1st value in column1 of Array1 = 1.61046126078761"

Actually that is the second element in Array1, not the first.

[SNT]

Hi Stephen! Oh yeah that's a mistake on my part

Answer 1

[Stephen23]

>> D = abs(bsxfun(@minus,Array1,Array2(:,1).'));
>> [~,X] = min(D,[],2);
>> Array3 = Array2(X,2)
Array3 =
 300
 400
 500
 400
 600
 600
 500
 500

[SNT]

Hi Stephen

Thank you very much for your reply. This works well! But could you help me understand what happens within this code section.

Thanks!

Sarala

[Stephen23]

D is the absolute values of the differences between all values in both input vectors. It is a matrix corresponding to the values of Array1 down the rows, and of Array2 across the columns.

X is the column index of the minimum value in each row of that matrix.

Then index X gets the required rows from Array2.

For more info on the specific operations read their documentation, and do the introductory tutorials:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

https://www.mathworks.com/matlabcentral/answers/228557-experts-of-matlab-how-did-you-learn-any-advice-for-beginner-intermediate-users

Answer 2

[Andrei Bobrov]

A = sortrows(Array2,1);
out = A(discretize(Array1,[-inf;A(1:end-1,1)+diff(A(:,1))/2;inf]),2);

[SNT]

Hi Andrei,

I had a few errors popping up

Cell contents assignment to a non-cell array object

So I added

      A={};

But then I get below error

Error using discretize Expected input number 2, edges, to be non-decreasing valued.

Error in discretize (line 54) validateattributes(edges, {'numeric','logical'},{'vector', 'real', ...

Error in CompareArrays (line 41) A{3} = A{2}(discretize(A{1},[-inf;A{2}(1:end-1,1)+diff(A{2}(:,1))/2;inf]),2);

Thanks!

Sarala

[Andrei Bobrov]

fixed