How to conditionality concat columns of a matrix?

Hi everyone,

My data set consists of 60 rows and 86 columns. First row is parameter values that are ranging from 1.2 to 1.73. I required to select columns based on the parameter values. In the below example, I select all the columns having parameter value between 1.2 and 1.3. However, it is a bit hard to compute this manully. May someone help me tyo automate this for a window of 0.5.

For exmaple, same process repeat for 1-1.5, 1.5-2, 2-2.5 and so on. and store mean parametere values in one matrix and selected columns in another matrix.

format short

% Lines below this are not important .........
X = load('PDS_case.csv'); % input data
C_sort = sortrows(X,5);
Tri = C_sort(1:86,:);
data1 = sortrows(Tri,7);
PDS=(data1(:,7));
dd=(PDS*1e8);
data2=data1(:,8:66);
Arr=[dd data2]
A=Arr';

% Lines below this are important ...........

TheArray=A; % Data set after preliminary processing 
C=1.0; % lower limit for parameter value 
D=1.5; % upper limit of the parametere values 
mask = (TheArray(1,:) < D & TheArray(1,:)>C); % Masking condition 
output = TheArray(:,mask); % selected array 
pds=mean (output(1,:)); % mean of the parameteres velues of the selected coloumns 
ev=output(2:end,:); % Delete parametere row from selected data
d1 = ev(:); % matrix converted to column matrix 

[Stephen23]

"same process repeat for 1-1.5, 1.5-2, 2-2.5 and so on"

Then you need to ignore any badly-written code written using loops to repeat code. That will not make your task easier.

A much better approach would use discretization functions to bin the data, e.g. HISTCOUNTS:

https://www.mathworks.com/help/matlab/ref/histcounts.html

Answer 1

[Santosh Fatale]

Hi Adnan,

I understand that you want to select columns of matrix TheArray according to the output of the logical array and find out the mean of selected range of parameter value. You also want to store columns from the matrix TheArray into another variable. I assumed that the window for comparison is 0.5. You can achieve the desired task using for loop as follows:

lowerLimit = 1.0; % minimum value of the parameter
UpperLimit = 10; % maximum value of the parameter
stepsSize = 0.5; % window length
rangeVec = lowerLimit:stepsSize:UpperLimit;

TheArray=A; % Data set after preliminary processing
pds = zeros(length(rangeVec)-1,1);

for iterVar = 1 : length(rangeVec)-1
    C = rangeVec(iterVar); % lower limit for parameter value 
    D = rangeVec(iterVar + 1) ; % upper limit of the parametere values 
    mask = (TheArray(1,:) < D & TheArray(1,:)>C); % Masking condition 
    output = TheArray(:,mask); % selected array 
    pds(iterVar) = mean(output(1,:)); % mean of the parameteres velues of the selected coloumns 
    ev = output(2:end,:); % Delete parametere row from selected data
    strVar = strcat('d',num2str(iterVar),'= ev(:)'); % creates string for input to the evalin function
    evalin('base',strVar); % matrix converted to column matrix
end

For more info, refer to the documentation of strcat, num2str, and evalin functions

[Stephen23]

"For more info, refer to the documentation of... " MATLAB:

https://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html