Draw circles at specific coordinates of a zero matrix

void randu (InputOutputArray dst, InputArray low, InputArray high)
Generates a single uniformly-distributed random number or an array of random numbers.

Parameters:

• dst – output array of random numbers; the array must be pre-allocated.
• low – inclusive lower boundary of the generated random numbers.
• high – exclusive upper boundary of the generated random numbers.

This is a program to draw circles at specific positions of a zero matrix.

Steps:

1. Get some random coordinates (matrix R with 15 points)
2. Create a zero matrix
3. Circle at each position
4. Show the result

Functions:

randu, circle, imshow, waitKey.

Example:

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#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include<iostream>

using namespace cv;
using namespace std;

int main( int argc, char** argv )
{
    Mat R = Mat(15, 2, CV_32FC1);
    randu(R, Scalar(0), Scalar(255));
    cout << "R = " << endl << " " << R << endl << endl; 

    Mat Z = Mat::zeros(300,300, CV_8UC3);

    for(int i=0;i<15;i++)
    {
        circle( Z, Point( R.at<float>(i, 0), R.at<float>(i, 1) ), 5,  Scalar(255,0,255), 2, 8, 0 );
    }
    imshow("zeros2",Z);

    waitKey(0);
    return 0;
}

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