Added matric

matrices.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+	"gonum.org/v1/gonum/mat"
+)
+
+func main() {
+	// Create a flat representation of our matrix.
+	components := []float64{1.2, -5.7, -2.4, 7.3}
+
+	// Form our matrix (the first argument is the number of
+	// rows and the second argument is the number of columns).
+	a := mat.NewDense(2, 2, components)
+
+	// As a sanity check, output the matrix to standard out.
+	fa := mat.Formatted(a, mat.Prefix(" "))
+	fmt.Printf("mat = %v\n\n", fa)
+
+	// Get a single value from the matrix.
+	val := a.At(0, 1)
+	fmt.Printf("The value of a at (0,1) is: %.2f\n\n", val)
+
+	// Get the values in a specific column.
+	col := mat.Col(nil, 0, a)
+	fmt.Printf("The values in the 1st column are: %v\n\n", col)
+
+	// Get the values in a kspecific row.
+	row := mat.Row(nil, 1, a)
+	fmt.Printf("The values in the 2nd row are: %v\n\n", row)
+
+	// Modify a single element.
+	a.Set(0, 1, 11.2)
+
+	// Modify an entire row.
+	a.SetRow(0, []float64{14.3, -4.2})
+
+	// Modify an entire column.
+	a.SetCol(0, []float64{1.7, -0.3})
+}

matrix_operation.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"fmt"
+	"gonum.org/v1/gonum/mat"
+	"log"
+	"math"
+)
+
+func main() {
+
+	// Create two matrices of the same size, a and b.
+	a := mat.NewDense(3, 3, []float64{1, 2, 3, 0, 4, 5, 0, 0, 6})
+	b := mat.NewDense(3, 3, []float64{8, 9, 10, 1, 4, 2, 9, 0, 2})
+
+	// Create a third matrix of a different size.
+	c := mat.NewDense(3, 2, []float64{3, 2, 1, 4, 0, 8})
+
+	// Add a and b.
+	d := mat.NewDense(3, 3, nil)
+	d.Add(a, b)
+	fd := mat.Formatted(d, mat.Prefix("            "))
+	fmt.Printf("d = a + b = %0.4v\n\n", fd)
+
+	// Multiply a and c.
+	f := mat.NewDense(3, 2, nil)
+	f.Mul(a, c)
+	ff := mat.Formatted(f, mat.Prefix("          "))
+	fmt.Printf("f = a c = %0.4v\n\n", ff)
+
+	// Raising a matrix to a power.
+	g := mat.NewDense(3, 3, nil)
+	g.Pow(a, 5)
+	fg := mat.Formatted(g, mat.Prefix("          "))
+	fmt.Printf("g = a^5 = %0.4v\n\n", fg)
+
+	// Apply a function to each of the elements of a.
+	h := mat.NewDense(3, 3, nil)
+	sqrt := func(_, _ int, v float64) float64 { return math.Sqrt(v) }
+	h.Apply(sqrt, a)
+	fh := mat.Formatted(h, mat.Prefix("              "))
+	fmt.Printf("h = sqrt(a) = %0.4v\n\n", fh)
+
+	// Create a new matrix a.
+	a = mat.NewDense(3, 3, []float64{1, 2, 3, 0, 4, 5, 0, 0, 6})
+
+	// Compute and output the transpose of the matrix.
+	ft := mat.Formatted(a.T(), mat.Prefix(" "))
+	fmt.Printf("a^T = %v\n\n", ft)
+
+	// Compute and output the determinant of a.
+	deta := mat.Det(a)
+	fmt.Printf("det(a) = %.2f\n\n", deta)
+
+	// Compute and output the inverse of a.
+	aInverse := mat.NewDense(3, 3, nil)
+	if err := aInverse.Inverse(a); err != nil {
+		log.Fatal(err)
+	}
+	fi := mat.Formatted(aInverse, mat.Prefix(" "))
+	fmt.Printf("a^-1 = %v\n\n", fi)
+
+}