Matrix multiplication using Jama library
I want to multiply 2 matrix using Jama library but 开发者_如何学运维it returns:
A col: 4 row: 4
B col: 1 row: 4
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Matrix dimensions must agree.
My code:
double[][] arrA = { {1,0,0,0}, {0, Math.cos(0.34), -Math.sin(0.34), 0}, {0, Math.sin(0.34), Math.cos(0.34), 0}, {0,0,0,1} };
double[][] arrB = { {x}, {y}, {z}, {1} };
Matrix A = new Matrix(arrA, 4, 4);
Matrix B = new Matrix(arrB, 4, 1);
A.print(1, 1);
B.print(1, 1);
System.out.println("A col: " + A.getColumnDimension() + " row: " + A.getRowDimension());
System.out.println("B col: " + B.getColumnDimension() + " row: " + B.getRowDimension());
Matrix C = A.arrayTimes(B);
You want to do A.times(B)
for matrix multiplication.
arrayTimes
is element by element multiplication.
For a deeper idea about JAMA, I really suggest: http://math.nist.gov/javanumerics/jama/doc/
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