I need to store these values from another function into an array

So this is my function which is calculating the number of keypoints from an image. So I have this file which has 8 images. I am comparing one of the image in the file with the others so I need to extract all the matching points between the images, and store those values of keypoints in an array for further processing.

SwSift is calling the function drawMatched that calculates the number of matched keypoints and prints it.

I am then accessing a folder of 8 images where I am matching one of the images with the rest.

I want to store these values in an array for further processing.

function [] = drawMatched( matched, img1, img2, loc1, loc2)
% Function: Draw matched points
% Create a new image showing the two images side by side.
img3 = appendimages(img1,img2);

% Show a figure with lines joining the accepted matches.
figure('Position', [100 100 size(img3,2) size(img3,1)]);
colormap gray;
imagesc(img3);
hold on;
cols1 = size(img1,2);
n = size(matched,2);
colors = ['c','m','y'];
colors_n = length(colors);
for i = 1: n
  if (matched(i) > 0)
    color = colors(randi(colors_n));
    line([loc1(i,2) loc2(matched(i),2)+cols1], ...
         [loc1(i,1) loc2(matched(i),1)], 'Color', color);
  end
end
    hold off;
    
    num = sum(matched > 0);
    fprintf('Found %d matches.\n', num);
   
end



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%% this is another code that calls the function in which drawMatched has been used%%%%%
function  keypoint = swSift(img1,img2)
% img1 = imread('1.jpg');
% img2 = imread('test.jpg');
[des1,loc1] = getFeatures(img1);
[des2,loc2] = getFeatures(img2);
matched = match(des1,des2);
% drawFeatures(img1,loc1);
% drawFeatures(img2,loc2);
drawMatched(matched,img1,img2,loc1,loc2);
global num
keypoint = num;
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%  Calling this function in another window which I am accessing files in a folder, applying swSift %%%
% % and i am getting number of matched key points %%%%
clear all
clc;
location = 'E:\ATR\*.JPG';        % folder in which your template images exists
img= imread('E:\ATR\gh_368053_209864_19.JPG');
ds = imageDatastore(location);    % Creates a datastore for all images in your folder
% fileNames={a.name};
while hasdata(ds) 
    temp = read(ds);              % read image from datastore
%   Image_name = temp.name;
%   figure, imshow(temp)
   keypoints = swSift(img,temp);
end

Answer 1

[KALYAN ACHARJYA]

Jus considering num as output arguments in the function.

function num=drawMatched( matched, img1, img2, loc1, loc2)
% Function: Draw matched points
% Create a new image showing the two images side by side.
img3 = appendimages(img1,img2);
% Show a figure with lines joining the accepted matches.
figure('Position', [100 100 size(img3,2) size(img3,1)]);
colormap gray;
imagesc(img3);
hold on;
cols1 = size(img1,2);
n = size(matched,2);
colors = ['c','m','y'];
colors_n = length(colors);
for i = 1: n
  if (matched(i) > 0)
    color = colors(randi(colors_n));
    line([loc1(i,2) loc2(matched(i),2)+cols1], ...
         [loc1(i,1) loc2(matched(i),1)], 'Color', color);
  end
end
    hold off;
    num=sum(matched > 0);
    fprintf('Found %d matches.\n', num);
end

##

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%% this is another code that calls the function in which drawMatched has been used%%%%%
function  keypoint = swSift(img1,img2)
% img1 = imread('1.jpg');
% img2 = imread('test.jpg');
[des1,loc1] = getFeatures(img1);
[des2,loc2] = getFeatures(img2);
matched = match(des1,des2);
% drawFeatures(img1,loc1);
% drawFeatures(img2,loc2);
keypoint=drawMatched(matched,img1,img2,loc1,loc2);
end

##

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%  Calling this function in another window which I am accessing files in a folder, applying swSift %%%
% % and i am getting number of matched key points %%%%
clear all
clc;
location = 'E:\ATR\*.JPG';        % folder in which your template images exists
img= imread('E:\ATR\gh_368053_209864_19.JPG');
ds = imageDatastore(location);    % Creates a datastore for all images in your folder
% fileNames={a.name};
l=1;
while hasdata(ds) 
    temp = read(ds);              % read image from datastore
%   Image_name = temp.name;
%   figure, imshow(temp)
   keypoints(l)= swSift(img,temp);
   l=l+1;
end
keypoints