+++ /dev/null
-// Copyright ©2013 The Gonum Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package mat
-
-import (
- "fmt"
- "strconv"
-)
-
-// Formatted returns a fmt.Formatter for the matrix m using the given options.
-func Formatted(m Matrix, options ...FormatOption) fmt.Formatter {
- f := formatter{
- matrix: m,
- dot: '.',
- }
- for _, o := range options {
- o(&f)
- }
- return f
-}
-
-type formatter struct {
- matrix Matrix
- prefix string
- margin int
- dot byte
- squeeze bool
-}
-
-// FormatOption is a functional option for matrix formatting.
-type FormatOption func(*formatter)
-
-// Prefix sets the formatted prefix to the string p. Prefix is a string that is prepended to
-// each line of output.
-func Prefix(p string) FormatOption {
- return func(f *formatter) { f.prefix = p }
-}
-
-// Excerpt sets the maximum number of rows and columns to print at the margins of the matrix
-// to m. If m is zero or less all elements are printed.
-func Excerpt(m int) FormatOption {
- return func(f *formatter) { f.margin = m }
-}
-
-// DotByte sets the dot character to b. The dot character is used to replace zero elements
-// if the result is printed with the fmt ' ' verb flag. Without a DotByte option, the default
-// dot character is '.'.
-func DotByte(b byte) FormatOption {
- return func(f *formatter) { f.dot = b }
-}
-
-// Squeeze sets the printing behaviour to minimise column width for each individual column.
-func Squeeze() FormatOption {
- return func(f *formatter) { f.squeeze = true }
-}
-
-// Format satisfies the fmt.Formatter interface.
-func (f formatter) Format(fs fmt.State, c rune) {
- if c == 'v' && fs.Flag('#') {
- fmt.Fprintf(fs, "%#v", f.matrix)
- return
- }
- format(f.matrix, f.prefix, f.margin, f.dot, f.squeeze, fs, c)
-}
-
-// format prints a pretty representation of m to the fs io.Writer. The format character c
-// specifies the numerical representation of of elements; valid values are those for float64
-// specified in the fmt package, with their associated flags. In addition to this, a space
-// preceding a verb indicates that zero values should be represented by the dot character.
-// The printed range of the matrix can be limited by specifying a positive value for margin;
-// If margin is greater than zero, only the first and last margin rows/columns of the matrix
-// are output. If squeeze is true, column widths are determined on a per-column basis.
-//
-// format will not provide Go syntax output.
-func format(m Matrix, prefix string, margin int, dot byte, squeeze bool, fs fmt.State, c rune) {
- rows, cols := m.Dims()
-
- var printed int
- if margin <= 0 {
- printed = rows
- if cols > printed {
- printed = cols
- }
- } else {
- printed = margin
- }
-
- prec, pOk := fs.Precision()
- if !pOk {
- prec = -1
- }
-
- var (
- maxWidth int
- widths widther
- buf, pad []byte
- )
- if squeeze {
- widths = make(columnWidth, cols)
- } else {
- widths = new(uniformWidth)
- }
- switch c {
- case 'v', 'e', 'E', 'f', 'F', 'g', 'G':
- if c == 'v' {
- buf, maxWidth = maxCellWidth(m, 'g', printed, prec, widths)
- } else {
- buf, maxWidth = maxCellWidth(m, c, printed, prec, widths)
- }
- default:
- fmt.Fprintf(fs, "%%!%c(%T=Dims(%d, %d))", c, m, rows, cols)
- return
- }
- width, _ := fs.Width()
- width = max(width, maxWidth)
- pad = make([]byte, max(width, 2))
- for i := range pad {
- pad[i] = ' '
- }
-
- first := true
- if rows > 2*printed || cols > 2*printed {
- first = false
- fmt.Fprintf(fs, "Dims(%d, %d)\n", rows, cols)
- }
-
- skipZero := fs.Flag(' ')
- for i := 0; i < rows; i++ {
- if !first {
- fmt.Fprint(fs, prefix)
- }
- first = false
- var el string
- switch {
- case rows == 1:
- fmt.Fprint(fs, "[")
- el = "]"
- case i == 0:
- fmt.Fprint(fs, "⎡")
- el = "⎤\n"
- case i < rows-1:
- fmt.Fprint(fs, "⎢")
- el = "⎥\n"
- default:
- fmt.Fprint(fs, "⎣")
- el = "⎦"
- }
-
- for j := 0; j < cols; j++ {
- if j >= printed && j < cols-printed {
- j = cols - printed - 1
- if i == 0 || i == rows-1 {
- fmt.Fprint(fs, "... ... ")
- } else {
- fmt.Fprint(fs, " ")
- }
- continue
- }
-
- v := m.At(i, j)
- if v == 0 && skipZero {
- buf = buf[:1]
- buf[0] = dot
- } else {
- if c == 'v' {
- buf = strconv.AppendFloat(buf[:0], v, 'g', prec, 64)
- } else {
- buf = strconv.AppendFloat(buf[:0], v, byte(c), prec, 64)
- }
- }
- if fs.Flag('-') {
- fs.Write(buf)
- fs.Write(pad[:widths.width(j)-len(buf)])
- } else {
- fs.Write(pad[:widths.width(j)-len(buf)])
- fs.Write(buf)
- }
-
- if j < cols-1 {
- fs.Write(pad[:2])
- }
- }
-
- fmt.Fprint(fs, el)
-
- if i >= printed-1 && i < rows-printed && 2*printed < rows {
- i = rows - printed - 1
- fmt.Fprintf(fs, "%s .\n%[1]s .\n%[1]s .\n", prefix)
- continue
- }
- }
-}
-
-func maxCellWidth(m Matrix, c rune, printed, prec int, w widther) ([]byte, int) {
- var (
- buf = make([]byte, 0, 64)
- rows, cols = m.Dims()
- max int
- )
- for i := 0; i < rows; i++ {
- if i >= printed-1 && i < rows-printed && 2*printed < rows {
- i = rows - printed - 1
- continue
- }
- for j := 0; j < cols; j++ {
- if j >= printed && j < cols-printed {
- continue
- }
-
- buf = strconv.AppendFloat(buf, m.At(i, j), byte(c), prec, 64)
- if len(buf) > max {
- max = len(buf)
- }
- if len(buf) > w.width(j) {
- w.setWidth(j, len(buf))
- }
- buf = buf[:0]
- }
- }
- return buf, max
-}
-
-type widther interface {
- width(i int) int
- setWidth(i, w int)
-}
-
-type uniformWidth int
-
-func (u *uniformWidth) width(_ int) int { return int(*u) }
-func (u *uniformWidth) setWidth(_, w int) { *u = uniformWidth(w) }
-
-type columnWidth []int
-
-func (c columnWidth) width(i int) int { return c[i] }
-func (c columnWidth) setWidth(i, w int) { c[i] = w }
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