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3fa9374bd4
This merges the three packages, matrix, mat64, and cmat128. It then renames this big package to mat. It fixes the import statements and corresponding code
113 lines
2.9 KiB
Go
113 lines
2.9 KiB
Go
// Copyright ©2015 The gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package mat_test
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import (
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"fmt"
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"gonum.org/v1/gonum/mat"
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)
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func ExampleFormatted() {
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a := mat.NewDense(3, 3, []float64{1, 2, 3, 0, 4, 5, 0, 0, 6})
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// Create a matrix formatting value with a prefix and calculating each column
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// width individually...
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fa := mat.Formatted(a, mat.Prefix(" "), mat.Squeeze())
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// and then print with and without zero value elements.
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fmt.Printf("with all values:\na = %v\n\n", fa)
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fmt.Printf("with only non-zero values:\na = % v\n\n", fa)
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// Modify the matrix...
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a.Set(0, 2, 0)
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// and print it without zero value elements.
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fmt.Printf("after modification with only non-zero values:\na = % v\n\n", fa)
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// Modify the matrix again...
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a.Set(0, 2, 123.456)
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// and print it using scientific notation for large exponents.
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fmt.Printf("after modification with scientific notation:\na = %.2g\n\n", fa)
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// See golang.org/pkg/fmt/ floating-point verbs for a comprehensive list.
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// Output:
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// with all values:
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// a = ⎡1 2 3⎤
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// ⎢0 4 5⎥
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// ⎣0 0 6⎦
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//
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// with only non-zero values:
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// a = ⎡1 2 3⎤
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// ⎢. 4 5⎥
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// ⎣. . 6⎦
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//
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// after modification with only non-zero values:
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// a = ⎡1 2 .⎤
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// ⎢. 4 5⎥
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// ⎣. . 6⎦
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//
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// after modification with scientific notation:
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// a = ⎡1 2 1.2e+02⎤
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// ⎢0 4 5⎥
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// ⎣0 0 6⎦
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}
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func ExampleExcerpt() {
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// Excerpt allows diagnostic display of very large
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// matrices and vectors.
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// The big matrix is too large to properly print...
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big := mat.NewDense(100, 100, nil)
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for i := 0; i < 100; i++ {
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big.Set(i, i, 1)
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}
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// so only print corner excerpts of the matrix.
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fmt.Printf("excerpt big identity matrix: %v\n\n",
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mat.Formatted(big, mat.Prefix(" "), mat.Excerpt(3)))
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// The long vector is also too large, ...
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long := mat.NewVector(100, nil)
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for i := 0; i < 100; i++ {
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long.SetVec(i, float64(i))
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}
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// ... so print end excerpts of the vector,
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fmt.Printf("excerpt long column vector: %v\n\n",
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mat.Formatted(long, mat.Prefix(" "), mat.Excerpt(3)))
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// or its transpose.
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fmt.Printf("excerpt long row vector: %v\n",
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mat.Formatted(long.T(), mat.Prefix(" "), mat.Excerpt(3)))
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// Output:
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// excerpt big identity matrix: Dims(100, 100)
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// ⎡1 0 0 ... ... 0 0 0⎤
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// ⎢0 1 0 0 0 0⎥
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// ⎢0 0 1 0 0 0⎥
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// .
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// .
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// .
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// ⎢0 0 0 1 0 0⎥
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// ⎢0 0 0 0 1 0⎥
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// ⎣0 0 0 ... ... 0 0 1⎦
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//
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// excerpt long column vector: Dims(100, 1)
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// ⎡ 0⎤
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// ⎢ 1⎥
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// ⎢ 2⎥
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// .
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// .
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// .
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// ⎢97⎥
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// ⎢98⎥
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// ⎣99⎦
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//
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// excerpt long row vector: Dims(1, 100)
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// [ 0 1 2 ... ... 97 98 99]
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}
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