Multiply Matrices

matrix-multiplication-js

function multiplyMatrix(A, B){
  
  console.log("****MULTIPLY****")
  let aRows = A.length
  let aCols = A[0].length
  let bRows = B.length
  let bCols = B[0].length
  let C = []
  let i = 0
  let j = 0
  
  for(i=0;i<aRows;i++){
    C.push([])
    for(j=0;j<bCols;j++){
      C[i].push(0)
    }
  }
  
  console.log(C)
  
  for(a=0;a<bCols;a++){
    for(i = 0; i < aRows; i++){
        let sum = 0
        for(j = 0; j < aCols; j++){
          sum += (A[i][j] * B[j][a]); 
        }
        
        C[i][a] = sum;
    }    
  }
  
  return C
}

function displayMatrix(matrix){
  
  console.log("*******matrix*******")
  console.log(matrix)
  let row = 0,
      col = 0;
  
    for(row = 0; row < matrix.length; row++){
      
      let rowString = ''
      for(col=0;col < matrix[row].length; col++){
        rowString = rowString + matrix[row][col] + ' '
      }
      console.log(rowString)
    }
}

var m = [[1,2,3],[4,5,6],[7,8,9]]

displayMatrix(m)

var A = [[1,2],
         [3,4]]
var B = [[2,0],
         [1,2]]

var C = multiplyMatrix(A, B, C)

displayMatrix(C)


A = [[1,3,2],
     [3,2,4]]
B = [[2,4],
     [0,1],
     [3,5]]

var C = multiplyMatrix(A, B, C)

displayMatrix(C)

A = [[1,2,3],
     [4,5,6]]
B = [[7,8],
     [9,10],
     [11,12]]

var C = multiplyMatrix(A, B, C)

displayMatrix(C)

A = [[3,4,2]]
B = [[13,9,7,15],
     [8,7,4,6],
     [6,4,0,3]]

var C = multiplyMatrix(A, B, C)

displayMatrix(C)