How to count repeated numbers and perform statistic on it?

Hi all,

I have a two column arrays where one represent time, the other are either 1, -1 or 0 which representing three different structures of my molecules.

for example of A = [

94.668 -1

94.67 1

94.672 -1

94.674 -1

94.676 0

94.678 1

94.68 -1

94.682 -1

94.684 -1

94.686 1

94.688 -1

94.69 1

94.692 -1

94.694 1

94.696 1

94.698 -1

94.7 -1

94.702 1

94.704 -1

94.706 -1

94.708 -1

94.71 1 ]

I want to count for example, structure(1) continuous of 2 array elements has how many of them, continuous of 3 array elements has how many of them, etc.

also the same statistic calculation for structure (-1) and structure (0).

so by looking at the above example, (-1) repeating 1 has 3, (-1) repeating 2 has 2 (-1) repeating 3 has 2, (0) repeating 1 has 1, (1) repeating 1 has 5, .....

the total length of my arays is 90000 X 2, which is large quantity of numbers to calculate manually, so may I as how can I write a matlab script to account for this problem?

Thank you !

Answer 1

[Image Analyst]

Try this:

A = [
    94.668  -1
    94.67  1
    94.672  -1
    94.674  -1
    94.676  0
    94.678  1
    94.68  -1
    94.682  -1
    94.684  -1
    94.686  1
    94.688  -1
    94.69  1
    94.692  -1
    94.694  1
    94.696  1
    94.698  -1
    94.7  -1
    94.702  1
    94.704  -1
    94.706  -1
    94.708  -1
    94.71  1 ];
% Find distribution of -1 runs.
mask = A(:, 2) == -1;
props = regionprops(mask, 'Area');
areaMinus1 = [props.Area];
subplot(3, 1, 1);
histogram(areaMinus1)
grid on;
title('Distribution of -1 runs')
xlabel('Run Length')
ylabel('Count')
drawnow;
% Find distribution of 0 runs.
mask = A(:, 2) == 0;
props = regionprops(mask, 'Area');
areas0 = [props.Area];
subplot(3, 1, 2);
histogram(areas0)
grid on;
title('Distribution of 0 runs')
xlabel('Run Length')
ylabel('Count')
drawnow;
% Find distribution of 1 runs.
mask = A(:, 2) == 1;
props = regionprops(mask, 'Area');
areas1 = [props.Area];
subplot(3, 1, 3);
histogram(areas1)
grid on;
title('Distribution of 1 runs')
xlabel('Run Length')
ylabel('Count')

drawnow;

[Xiu Wen Kang]

Hi Image Analyst,

Thank you so much for your help! :)

May I ask how do you export the arrays used to plot the histograms in your 3 figures?

Thanks !

[Image Analyst]

You can use writetable to write the data to a text file:

% Demo by Image Analyst
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format short g;
format compact;
fontSize = 22;
markerSize = 20;
A = [
    94.668  -1
    94.67  1
    94.672  -1
    94.674  -1
    94.676  0
    94.678  1
    94.68  -1
    94.682  -1
    94.684  -1
    94.686  1
    94.688  -1
    94.69  1
    94.692  -1
    94.694  1
    94.696  1
    94.698  -1
    94.7  -1
    94.702  1
    94.704  -1
    94.706  -1
    94.708  -1
    94.71  1 ];

% Find distribution of -1 runs.
mask = A(:, 2) == -1;
props = regionprops(mask, 'Area');
areaMinus1 = [props.Area];
subplot(3, 1, 1);
histObjectMinus1 = histogram(areaMinus1)
grid on;
title('Distribution of -1 runs')
xlabel('Run Length')
ylabel('Count')
drawnow;

% Find distribution of 0 runs.
mask = A(:, 2) == 0;
props = regionprops(mask, 'Area');
areas0 = [props.Area];
subplot(3, 1, 2);
histObject0 = histogram(areas0)
grid on;
title('Distribution of 0 runs')
xlabel('Run Length')
ylabel('Count')
drawnow;

% Find distribution of 1 runs.
mask = A(:, 2) == 1;
props = regionprops(mask, 'Area');
areas1 = [props.Area];
subplot(3, 1, 3);
histObject1 = histogram(areas1)
grid on;
title('Distribution of 1 runs')
xlabel('Run Length')
ylabel('Count')
drawnow;

% Export histogram to a file.  Here just doing the last histogram but you can do it for all 3 of them if you want.
outputFileName = 'delete me.txt'; % Or 'hist1.csv' or whatever you want.
t = table(histObject1.BinEdges(1:end-1)', histObject1.Values',...
    'VariableNames', {'LeftBinEdge', 'Count'})
writetable(t, outputFileName);
winopen(outputFileName)

[Xiu Wen Kang]

Thanks for your help!

I will give it a go :)