Code viewer for World: Character recognition neur...

// Cloned by Karl Murphy on 26 Nov 2019 from World "Character recognition neural network" by "Coding Train" project 
// Please leave this clone trail here.
 

// Port of Character recognition neural network from here:
// https://github.com/CodingTrain/Toy-Neural-Network-JS/tree/master/examples/mnist
// with many modifications 


// --- defined by MNIST - do not change these ---------------------------------------

const PIXELS        = 28;                       // images in data set are tiny 
const PIXELSSQUARED = PIXELS * PIXELS;

// number of training and test exemplars in the data set:
const NOTRAIN = 60000;
const NOTEST  = 10000;



//--- can modify all these --------------------------------------------------

// no of nodes in network 
const noinput  = PIXELSSQUARED;
const nohidden = 60;
const nooutput = 10;

const learningrate = 0.1;   // default 0.1  

// should we train every timestep or not 
let do_training = true;

// how many to train and test per timestep 
const TRAINPERSTEP = 30;
const TESTPERSTEP  = 5;

// multiply it by this to magnify for display 
const ZOOMFACTOR    = 7;                        
const ZOOMPIXELS    = ZOOMFACTOR * PIXELS; 

const ZOOMPIXELSSQUARED = ZOOMPIXELS * ZOOMPIXELS

// 3 rows of
// large image + 50 gap + small image    
// 50 gap between rows 

const canvaswidth = ( PIXELS + ZOOMPIXELS ) + 50;
//console.log("CANVAS WI " + canvaswidth);
const canvasheight = ( ZOOMPIXELS * 3 ) + 100;
//console.log("CANVAS hI " + canvas);

const DOODLE_THICK = 18;    // thickness of doodle lines 
const DOODLE_BLUR = 2;      // blur factor applied to doodles 


let mnist;      
// all data is loaded into this 
// mnist.train_images
// mnist.train_labels
// mnist.test_images
// mnist.test_labels


let nn;

let trainrun = 1;
let train_index = 0;

let testrun = 1;
let test_index = 0;
let total_tests = 0;
let total_correct = 0;

// images in LHS:
let doodle, demo;
let doodle_exists = false;
//doodle_finished = false;
let demo_exists = false;

let mousedrag = false;      // are we in the middle of a mouse drag drawing?  


// save inputs to global var to inspect
// type these names in console 
var train_inputs, test_inputs, demo_inputs, doodle_inputs;


// Matrix.randomize() is changed to point to this. Must be defined by user of Matrix. 

function randomWeight()
{
    return ( AB.randomFloatAtoB ( -0.5, 0.5 ) );
            // Coding Train default is -1 to 1
}    



// CSS trick 
// make run header bigger 
 $("#runheaderbox").css ( { "max-height": "95vh" } );



//--- start of AB.msgs structure: ---------------------------------------------------------
// We output a serious of AB.msgs to put data at various places in the run header 
var thehtml;

  // 1 Doodle header 
  thehtml = "<hr> <h1> 1. Doodle </h1> Top row: Doodle (left) and shrunk (right). <br> " +
        " Draw your doodle in top LHS. <button onclick='wipeDoodle();' class='normbutton' >Clear doodle</button> <br> ";
   AB.msg ( thehtml, 1 );

  // 2 Doodle variable data (guess)
  
  // 3 Training header
  thehtml = "<hr> <h1> 2. Training </h1> Middle row: Training image magnified (left) and original (right). <br>  " +
        " <button onclick='do_training = false;' class='normbutton' >Stop training</button> <br> ";
  AB.msg ( thehtml, 3 );
     
  // 4 variable training data 
  
  // 5 Testing header
  thehtml = "<h3> Hidden tests </h3> " ;
  AB.msg ( thehtml, 5 );
           
  // 6 variable testing data 
  
  // 7 Demo header 
  thehtml = "<hr> <h1> 3. Demo </h1> Bottom row: Test image magnified (left) and  original (right). <br>" +
        " The network is <i>not</i> trained on any of these images. <br> " +
        " <button onclick='makeDemo();' class='normbutton' >Demo test image</button> <br> ";
   AB.msg ( thehtml, 7 );
   
  // 8 Demo variable data (random demo ID)
  // 9 Demo variable data (changing guess)
  
const greenspan = "<span style='font-weight:bold; font-size:x-large; color:darkgreen'> "  ;

//--- end of AB.msgs structure: ---------------------------------------------------------




function setup() 
{
  createCanvas ( canvaswidth, canvasheight );

  //https://p5js.org/reference/#/p5/createGraphics
  doodle = createGraphics ( ZOOMPIXELS  , ZOOMPIXELS );       // doodle on larger canvas 
  doodle.pixelDensity(1);
  //Karl Murphy code
  doodle.canvas.id = "doodle_canvas";
  
// JS load other JS 
// maybe have a loading screen while loading the JS and the data set 

  AB.loadingScreen();
 
 //Karl Murphy code
 $.getScript ( "/uploads/codingtrain/matrix.js", function()
 {
   $.getScript ( "uploads/kmurfi/opencv.js", function()
   {
        $.getScript ( "uploads/kmurfi/nn.js", function()
   {
        $.getScript ( "/uploads/codingtrain/mnist.js", function()
        {
            console.log ("All JS loaded");
            nn = new NeuralNetwork(  noinput, nohidden, nooutput );
            nn.setLearningRate ( learningrate );
            loadData();
        });
   });
 });
 });
}



// load data set from local file (on this server)

function loadData()    
{
  loadMNIST ( function(data)    
  {
    mnist = data;
    console.log ("All data loaded into mnist object:")
    console.log(mnist);
    AB.removeLoading();     // if no loading screen exists, this does nothing 
  });
}



function getImage ( img )      // make a P5 image object from a raw data array   
{
    let theimage  = createImage (PIXELS, PIXELS);    // make blank image, then populate it 
    theimage.loadPixels();        
    
    for (let i = 0; i < PIXELSSQUARED ; i++) 
    {
        let bright = img[i];
        let index = i * 4;
        theimage.pixels[index + 0] = bright;
        theimage.pixels[index + 1] = bright;
        theimage.pixels[index + 2] = bright;
        theimage.pixels[index + 3] = 255;
    }
    
    theimage.updatePixels();
    return theimage;
}


function getInputs ( img )      // convert img array into normalised input array 
{
    let inputs = [];
    for (let i = 0; i < PIXELSSQUARED ; i++)          
    {
        let bright = img[i];
        inputs[i] = bright / 255;       // normalise to 0 to 1
    } 
    return ( inputs );
}

 

function trainit (show)        // train the network with a single exemplar, from global var "train_index", show visual on or off 
{
  let img   = mnist.train_images[train_index];
  let label = mnist.train_labels[train_index];
  
  // optional - show visual of the image 
  if (show)                
  {
    var theimage = getImage ( img );    // get image from data array 
    image ( theimage,   0,                ZOOMPIXELS+50,    ZOOMPIXELS,     ZOOMPIXELS  );      // magnified 
    image ( theimage,   ZOOMPIXELS+50,    ZOOMPIXELS+50,    PIXELS,         PIXELS      );      // original
  }

  // set up the inputs
  let inputs = getInputs ( img );       // get inputs from data array 

  // set up the outputs
  let targets = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
  targets[label] = 1;       // change one output location to 1, the rest stay at 0 

  // console.log(train_index);
  // console.log(inputs);
  // console.log(targets);

  train_inputs = inputs;        // can inspect in console 
  nn.train ( inputs, targets );

  thehtml = " trainrun: " + trainrun + "<br> no: " + train_index ;
  AB.msg ( thehtml, 4 );

  train_index++;
  if ( train_index == NOTRAIN ) 
  {
    train_index = 0;
    console.log( "finished trainrun: " + trainrun );
    trainrun++;
  }
}


function testit()    // test the network with a single exemplar, from global var "test_index"
{ 
  let img   = mnist.test_images[test_index];
  let label = mnist.test_labels[test_index];

  // set up the inputs
  let inputs = getInputs ( img ); 
  
  test_inputs = inputs;        // can inspect in console 
  let prediction    = nn.predict(inputs);       // array of outputs 
  let guess         = findMax(prediction);      // the top output 

  total_tests++;
  if (guess == label)  total_correct++;

  let percent = (total_correct / total_tests) * 100 ;
  
  thehtml =  " testrun: " + testrun + "<br> no: " + total_tests + " <br> " +
        " correct: " + total_correct + "<br>" +
        "  score: " + greenspan + percent.toFixed(2) + "</span>";
  AB.msg ( thehtml, 6 );

  test_index++;
  if ( test_index == NOTEST ) 
  {
    console.log( "finished testrun: " + testrun + " score: " + percent.toFixed(2) );
    testrun++;
    test_index = 0;
    total_tests = 0;
    total_correct = 0;
  }
}




//--- find no.1 (and maybe no.2) output nodes ---------------------------------------
// (restriction) assumes array values start at 0 (which is true for output nodes) 


function find12 (a)         // return array showing indexes of no.1 and no.2 values in array 
{
  let no1 = 0;
  let no2 = 0;
  let no1value = 0;     
  let no2value = 0;
  
  for (let i = 0; i < a.length; i++) 
  {
    if (a[i] > no1value) 
    {
      no1 = i;
      no1value = a[i];
    }
    else if (a[i] > no2value) 
    {
      no2 = i;
      no2value = a[i];
    }
  }
  
  var b = [ no1, no2 ];
  return b;
}


// just get the maximum - separate function for speed - done many times 
// find our guess - the max of the output nodes array

function findMax (a)        
{
  let no1 = 0;
  let no1value = 0;     
  
  for (let i = 0; i < a.length; i++) 
  {
    if (a[i] > no1value) 
    {
      no1 = i;
      no1value = a[i];
    }
  }
  
  return no1;
}




// --- the draw function -------------------------------------------------------------
// every step:

// function mouseReleased() {
//   console.log("suc");
// }

 
function draw() 
{
  // check if libraries and data loaded yet:
  if ( typeof mnist == 'undefined' ) return;


// how can we get white doodle on black background on yellow canvas?
//        background('#ffffcc');    doodle.background('black');

      background ('black');
    
if ( do_training )    
{
  // do some training per step 
    for (let i = 0; i < TRAINPERSTEP; i++) 
    {
      if (i == 0)    trainit(true);    // show only one per step - still flashes by  
      else           trainit(false);
    }
    
  // do some testing per step 
    for (let i = 0; i < TESTPERSTEP; i++) 
      testit();
}

  // keep drawing demo and doodle images 
  // and keep guessing - we will update our guess as time goes on 
  
  if ( demo_exists )
  {
    drawDemo();
    guessDemo();
  }
  if ( doodle_exists ) 
  {
    drawDoodle();
    guessDoodle();
  }
//   if (doodle_finished){
//       guessDoodle();
//   }


// detect doodle drawing 
// (restriction) the following assumes doodle starts at 0,0 
  
  if ( mouseIsPressed )         // gets called when we click buttons, as well as if in doodle corner  
  {
     // console.log ( mouseX + " " + mouseY + " " + pmouseX + " " + pmouseY );
     var MAX = ZOOMPIXELS + 20;     // can draw up to this pixels in corner 
     if ( (mouseX < MAX) && (mouseY < MAX) && (pmouseX < MAX) && (pmouseY < MAX) )
     {
        mousedrag = true;       // start a mouse drag 
        doodle_exists = true;
        //doodle.textAlign(CENTER);
        doodle.stroke('white');
        doodle.strokeWeight( DOODLE_THICK );
        doodle.line(mouseX, mouseY, pmouseX, pmouseY);      
     }
  }
  else 
  {
      // are we exiting a drawing
      if ( mousedrag )
      {
            mousedrag = false;
            //doodle_finished = true;
            // console.log ("Exiting draw. Now blurring.");
            doodle.filter (BLUR, DOODLE_BLUR);    // just blur once 
            //   console.log (doodle);
      }
  }
}




//--- demo -------------------------------------------------------------
// demo some test image and predict it
// get it from test set so have not used it in training


function makeDemo()
{
    demo_exists = true;
    var  i = AB.randomIntAtoB ( 0, NOTEST - 1 );  
    
    demo        = mnist.test_images[i];     
    var label   = mnist.test_labels[i];
    
   thehtml =  "Test image no: " + i + "<br>" + 
            "Classification: " + label + "<br>" ;
   AB.msg ( thehtml, 8 );
   
   // type "demo" in console to see raw data 
}


function drawDemo()
{
    var theimage = getImage ( demo );
     //  console.log (theimage);
     
    image ( theimage,   0,                canvasheight - ZOOMPIXELS,    ZOOMPIXELS,     ZOOMPIXELS  );      // magnified 
    image ( theimage,   ZOOMPIXELS+50,    canvasheight - ZOOMPIXELS,    PIXELS,         PIXELS      );      // original
}


function guessDemo()
{
   let inputs = getInputs ( demo ); 
   
  demo_inputs = inputs;  // can inspect in console 
  
  let prediction    = nn.predict(inputs);       // array of outputs 
  let guess         = findMax(prediction);      // the top output 

   thehtml =   " We classify it as: " + greenspan + guess + "</span>" ;
   AB.msg ( thehtml, 9 );
}




//--- doodle -------------------------------------------------------------

function drawDoodle()
{
    // doodle is createGraphics not createImage
    let theimage = doodle.get();
    // console.log (theimage);
    
    image ( theimage,   0,                0,    ZOOMPIXELS,     ZOOMPIXELS  );      // original 
    image ( theimage,   ZOOMPIXELS+50,    0,    PIXELS,         PIXELS      );      // shrunk
}


//Karl Murphy code
function centerOfMass (img)
{
    sum_x = 0;
    sum_y = 0;
    num  = 0; 

    for (i=0; i<PIXELS; i++)
    {
        for (j=0; j<PIXELS; j++)
        {
            if (img[i + (j * PIXELS)] == 1)
            {
              sum_x = sum_x + i;
              sum_x = sum_y + j; 
              num = num+1;
            }
        }
    }

    sum_x = sum_x / num;
    sum_y = sum_y / num;
    
    return {"x": sum_x, "y": sum_y};
}

//Karl Murphy code
function oned_to_2d_array(oned_array, elements_per_each_array) {
    var matrix = [], i, k;

    for (i = 0, k = -1; i < oned_array.length; i++) {
        if (i % elements_per_each_array === 0) {
            k++;
            matrix[k] = [];
        }

        matrix[k].push(oned_array[i]);
    }

    return matrix;
}

//Karl Murphy code
function oned_to_2d_array_with_padding(oned_array, elements_per_each_array, factors, matrix) {
    
    top_rows_with_zeros = Math.ceil((28 - factors.rows) / 2);
    bottom_rows_with_zeros = Math.ceil(28 - ((28 - factors.rows) / 2)) ;
    left_cols_with_zeros = Math.ceil((28 - factors.cols) / 2);
    right_cols_with_zeros = Math.ceil(28 - ((28 - factors.cols) / 2));
    
    console.log("bottom_rows_with_zeros" + bottom_rows_with_zeros);
    console.log("left_cols_with_zeros" + left_cols_with_zeros);
    
    for (var i = 0;i<28;i++){
        
        for (var j = 0;j<28;i++){
            
           // matrix[i][j] = 0;
        
    }
        
    }
    
    // index = 0;
    
    // for (var x = top_rows_with_zeros;i<bottom_rows_with_zeros;i++){
        
    //     for (var y = left_cols_with_zeros;j<right_cols_with_zeros;i++){
            
    //         matrix[i][j] = oned_array[index];
    //         index = index + 1;
           
        
        
    // }
        
    // }  
    // return matrix;
    
}


//Karl Murphy code
function find_top_rows_to_delete(the_array){
    
    rows_to_delete = 0
    
    for(var i = 0; i < the_array.length; i++) 
    {
        var row = the_array[i];
        for(var j = 0; j < row.length; j++) 
        {
            if (row[j] !== 0){
                return rows_to_delete;
            }
        }
    rows_to_delete = i + 1;
    }
}

//Karl Murphy code
function find_bottom_rows_to_delete(the_array){
    
    rows_to_delete = 27
    
    for(var i = the_array.length -1; i > 0; i--)     {
        var row = the_array[i];
        for(var j = 0; j < row.length; j++) 
        {
            if (row[j] !== 0){
                return rows_to_delete;
            }
        }
    rows_to_delete = i - 1;
    }
}

//Karl Murphy code
function find_left_columns_to_delete(the_array){
    
    left_colums_to_delete = 0
    
    for(var i = 0; i < 28; i++) 
    {
        for(var j = 0; j < 28; j++) 
        {
            if (the_array[j][i] !== 0){
                return left_colums_to_delete;
            }
        }
    left_colums_to_delete = i + 1;
    }
}

//Karl Murphy code
function find_right_columns_to_delete(the_array){
    
    right_colums_to_delete = 27
    
    for(var i = 27; i > 0 ; i--) 
    {
        for(var j = 0; j < 28; j++) 
        {
            if (the_array[j][i] !== 0){
                return right_colums_to_delete;
            }
        }
    right_colums_to_delete = i - 1;
    }
}

//Karl Murphy code
function find_blank_rows_and_columns(matrix){

  start_row_point = find_top_rows_to_delete(matrix);
  //console.log("top_rows_to_delete " + start_row_point);
  
  end_row_point = find_bottom_rows_to_delete(matrix);
  //console.log("bottom_rows_to_delete " + end_row_point);

  
  start_column_point = find_left_columns_to_delete(matrix);
  //console.log("left_columns_to_delete " + start_column_point);
  
  end_column_point = find_right_columns_to_delete(matrix);
  //console.log("right_columns_to_delete " + end_column_point);
  
  //New matrix dimensions
  matrix_rows = (end_row_point - start_row_point) + 1
  matrix_columns = (end_column_point - start_column_point) + 1
  
  return {"rows" : matrix_rows,
          "columns": matrix_columns,
          "start_row_point": start_row_point,
          "end_row_point": end_row_point,
          "start_column_point": start_column_point,
          "end_column_point": end_column_point
  }
 
}

//Karl Murphy code
function create_2d_array(rows) {
  var arr = [];

  for (var i=0;i<rows;i++) {
     arr[i] = [];
  }

  return arr;
}

//Karl Murphy code
function resize_array(mat_dims){
    
    if (mat_dims.rows > mat_dims.columns){
        factor = 20.0/mat_dims.rows
        //console.log("in if ..factor == " + factor);
        rows = 20
        cols = Math.ceil(mat_dims.columns*factor)

    }
    else{
        factor = 20.0/mat_dims.columns
        cols = 20
        //console.log("in else ...factor == " + factor);
        rows = Math.ceil(mat_dims.rows*factor)
}
   return {"rows": rows, "cols": cols};
}

//Karl Murphy code
function copy_non_zero_rows_to_new_matrix(old_matrix, new_matrix, mat_dims ){
    
    for(var i = mat_dims.start_row_point, x = 0; i <=  mat_dims.end_row_point; x++, i++) 
    {
        var row = old_matrix[i];
        for(var j = mat_dims.start_column_point, y=0; j <= mat_dims.end_column_point; y++, j++) 
        {
            new_matrix[x][y] = row[j];
        }
    }
    
    return new_matrix;
    
}

//Karl Murphy code
function get_padding_amounts(factors){
  
  
  top_rows = Math.floor((28 - factors.rows) / 2);
  bottom_rows = Math.ceil((28 - factors.rows) / 2);

  left_cols_padding = Math.floor((28 - factors.cols) / 2);
  right_cols_padding = Math.ceil((28 - factors.cols) / 2);
  
  return {"top_rows": top_rows,
          "bottom_rows": bottom_rows,
          "left_cols_padding": left_cols_padding,
          "right_cols_padding": right_cols_padding}

}

//Karl Murphy code
function convert_mat_image_to_2d_array(mat_image, matrix){
    
    for(let i = 0; i < mat_image.rows; i++){
        for(let j = 0; j < mat_image.cols; j++){
            matrix[i][j] = mat_image.data[i*j*4];
        }
    }
    
    return matrix;
}

//Karl Murphy code
function strip_out_zeros(mat_dims, matrix){

    let arr = [];
    
    for (let i = mat_dims.start_row_point; i <= mat_dims.end_row_point ; i++){
        for (let j = mat_dims.start_column_point; j<= mat_dims.end_column_point ; j++){
            arr.push(matrix[i][j]);
        }
    }
    return arr;
}


/*
Karl Murphy code
Replicate steps found here - https://medium.com/@o.kroeger/tensorflow-mnist-and-your-own-handwritten-digits-4d1cd32bbab4
*/
function guessDoodle() 
{

   
   // doodle is createGraphics not createImage
//   let img = doodle.get();
//   img.resize ( PIXELS, PIXELS );
//   img.loadPixels();
  
  //STEP 1 - read image in grayscale mode
  let gray_scaled_image= cv.imread("doodle_canvas", cv.CV_LOAD_IMAGE_GRAYSCALE);
 
  //STEP 2
  //Rescale the image to 28*28px
  let image_28_px = new cv.Mat();
  let dsize = new cv.Size(28, 28);
  cv.resize(gray_scaled_image, image_28_px, dsize, 0, 0, cv.INTER_AREA);
  gray_scaled_image.delete();
  //console.log(rescaled_28_px);
  
  //let ret2;
  //let dst = new cv.Mat();
  //ret2,grey = cv.threshold(rescaled_28_px, dst, 127, 255, cv.THRESH_BINARY);
  //ret2,grey = cv.threshold(grey,0,255,cv.THRESH_BINARY | cv.THRESH_OTSU)
  
  //Convert MAT IMAGE to 2d array
  let matrix_28_px = create_2d_array(28);
  matrix_28_px = convert_mat_image_to_2d_array(image_28_px, matrix_28_px);
  console.log("matrix_28_px");
  console.log(matrix_28_px);
  
  
  //STEP 3a- Attempt to remove zeros (black) around image and resize the image to 20 * 20px
  matrix_dimensions = find_blank_rows_and_columns(matrix_28_px);
  console.log("matrix_dimensions");
  console.log(matrix_dimensions);
  
  //new_matrix = create_2d_array(matrix_dimensions.rows);
  
//   new_array_without_zeros = strip_out_zeros(matrix_dimensions, matrix_28_px)
//   console.log("new_array_without_zeros");
//   console.log(new_array_without_zeros);
  
  
//   let mat_XXX = cv.matFromArray(matrix_dimensions.rows, matrix_dimensions.columns, cv.CV_8U, new_array_without_zeros)
//   console.log("mat_XXX");
//   console.log(mat_XXX);
  
  factors = resize_array(matrix_dimensions);
  console.log("factors");
  console.log(factors);
  
  
  let image_20_px = new cv.Mat();
  dsize = new cv.Size(factors.cols, factors.rows);
  cv.resize(image_28_px, image_20_px, dsize, 0, 0, cv.INTER_AREA);
  console.log("image_20_px");
  console.log(image_20_px);
  
  //Convert MAT IMAGE to 2d array
//   let xxx = create_2d_array(20);
//   matrix_28_px = convert_mat_image_to_2d_array(rescaled_20_px, xxx);
//   console.log(xxx);
  
//   A = new cv.Mat(20, 20, cv.CV_8U, xxx ); //for 2D array
//   console.log("A");
//   console.log(A);
  
  //STEP 3b - Insert inner 20*20px box in to a outer 28*28px box and pad around the inner box with zeros
  let padded_image_28_px = new cv.Mat();
  let s = new cv.Scalar(0, 0, 0, 255);
  p = get_padding_amounts(factors)
  console.log("padding amounts");
  console.log(p);
  console.log(padded_image_28_px);
  cv.copyMakeBorder(image_20_px, padded_image_28_px, p.top_rows, p.bottom_rows, p.left_cols_padding, p.right_cols_padding, cv.BORDER_CONSTANT, s);
  
  
  //Convert MAT IMAGE to 2d array
  let ppp = create_2d_array(28);
  ppp_x = convert_mat_image_to_2d_array(padded_image_28_px, ppp);
  console.log("ppp_x");
  console.log(ppp_x);
  
  //console.log(padded_28_px);
  
  // set up inputs   
//   let inputs = [];
//   for (let i = 0; i < PIXELSSQUARED ; i++) 
//   {
//      inputs[i] = rescaled_28_px.data[i * 4];
//   }
  
  //console.log(rescaled_28_px);
  
  //old_matrix_28_px = oned_to_2d_array(inputs, 28); 
  //console.log(old_matrix_28_px);
  //console.log(old_matrix[12][2]);
  
  
  //console.log("new_rescaled_20_px");
  //console.log(new_rescaled_20_px);
  
  let inputs = [];
  for (let i = 0; i < PIXELSSQUARED ; i++) 
  {
      inputs[i] = padded_image_28_px.data[i * 4]/255;
  }
  
//   new_2d_array = create_2d_array(28)
//   nmm = oned_to_2d_array_with_padding(k_inputs, 28, factors, new_2d_array);
//   console.log(nnm);
  
  //console.log(k_inputs);
  
  
//   cv.resize(rescaled_28_px, rescaled_20_px, fx=factors.rows, fy=factors.cols, cv.INTER_AREA);
  
//   console.log(rescaled_20_px);
  
//   img.resize(factors.rows, factors.cols);
//   console.log(img);
  
  
  
  //cloned_array = copy_non_zero_rows_to_new_matrix(old_matrix, new_matrix, matrix_dimensions );
  //console.log("CLONED ARRAY" + cloned_array);
  
//   centre_of_mass = centerOfMass (inputs);
//   console.log(centre_of_mass);
  
  doodle_inputs = inputs;     // can inspect in console 

  //feed forward to make prediction 
  let prediction    = nn.predict(inputs);       // array of outputs 
  let b             = find12(prediction);       // get no.1 and no.2 guesses  

  thehtml =   " We classify it as: " + greenspan + b[0] + "</span> <br>" +
            " No.2 guess is: " + greenspan + b[1] + "</span>";
  AB.msg ( thehtml, 2 );
}


function wipeDoodle()    
{
    doodle_exists = false;
    doodle.background('black');
}




// --- debugging --------------------------------------------------
// in console
// showInputs(demo_inputs);
// showInputs(doodle_inputs);


function showInputs ( inputs )
// display inputs row by row, corresponding to square of pixels 
{
    var str = "";
    for (let i = 0; i < inputs.length; i++) 
    {
      if ( i % PIXELS == 0 )    str = str + "\n";                                   // new line for each row of pixels 
      var value = inputs[i];
      str = str + " " + value.toFixed(2) ; 
    }
    console.log (str);
}