How to pick the values from individual grids ?

Hi everyone,

May someone help me here ,,

My data set is consists of three paramateres ... x, y and z ..

the x, y paramteres are grided at an interval of 0.005, This give me a matrix of 16 by 16 grid ..

In each grid z-values are placed. Now I want to calculate the the z vales in each grid ...

The figure show the pictorial representation of data in each grid ... My task is to generate an output file with 256 columns and each colum give us the values of point placed in each grid ..

Thank you

clear all
%clc
a=xlsread('data');
x=a(:,1);% x parameter
y=a(:,2); %y parameter
z=a(:,3); % z parameter
%Grid scale 
x2=-130.04:0.005:-129.96;
y2=45.91:0.005:45.99;

[KSSV]

How different is your question from the previous asked question?

https://in.mathworks.com/matlabcentral/answers/592294-data-picking-from-grid?s_tid=prof_contriblnk

[aa]

In previous time I just want to plot data in grids ... But now I want to pick the values palced in each grid ...

[KSSV]

Dear friend....the old question's answer already shows you how to pick the data. You can plot the data only after picking the points.

[aa]

I am agree with you ... I have attempted multiple time to extract the data in each grid but still unsuccessful. May you help me here ...

[Turlough Hughes]

You can store the data in a cell array, so from the previous question that would just be

zStore{i,j} = z(idx); % place in the inner loop after idx is determined.

assuming you want to store z values only.

[aa]

great ... this works ... but its a grid of 16 by 16 .. if I want to check data in each grid point i have to click each grid one by one ... is it possible to get an output in excel sheet in 256 colums

[Walter Roberson]

The different columns would have to have different lengths. How would you like that to be dealt with?

[aa]

Yes ,,, with a Nan for empity cells.

Answer 1

[Turlough Hughes]

The objective is to create an excel sheet with columns of data having different length. You can store data that has different lengths in a cell array as mentioned in the comments by inserting following line into the answer provided by KSSV after idx has been determined in the inner loop:

zStore{1,j+(n-1)*(i-1)} = z(idx); % inside the loop

To demo the problem one can alternatively generate an example of zStore with the following:

for c = 1:256
    N = randi([50 200],1);
    zStore{1,c} = rand(N,1);
end

Convert zStore to a matrix padded with NaNs so that all columns have the same length as the longest column vector in zStore:

N = max(cellfun(@numel,zStore));
zMat = nan(N,256);
for i = 1:numel(zStore)
    zMat(1:numel(zStore{1,i}),i) = zStore{1,i};
end

Then you can write the matrix out to an excel sheet

writematrix(zMat,'data.xlsx')

[aa]

Hi,

I have attempted with the code you have provide dbut still did not get the expected output ...

May you help me here

[Turlough Hughes]

I've edited the line that goes inside the loop to store z values. Let me know if that works for you.