def rescale_row(self, i: int, s) -> HtmlFragment:
"""Replace i-th row of self by s times i-th row of self. The operation is done in place."""
return HtmlFragment(''.join([r'\[',
self._latex_(),
self._format_row_operations(self._rescale_row(i, s)),
r'\rightarrow',
self._latex_() + r'\]']))
def lu_swap(self, r1: int, r2: int) -> HtmlFragment:
"""Swap rows r1 and r2 of self, up to second diagonal.
Used in LUP factorization. This operation is done in place."""
return HtmlFragment(''.join([r'\[',
self._latex_(),
self._format_row_operations(self._lu_swap(r1, r2)),
r'\rightarrow',
self._latex_(),
r'\]']))
def swap_rows(self, r1: int, r2: int) -> HtmlFragment:
"""Swap rows r1 and r2 of self. The operation is done in place."""
return HtmlFragment(''.join([r'\[',
self._latex_(),
self._format_row_operations(self._swap_rows(r1, r2)),
r'\rightarrow',
self._latex_(),
r'\]']))
def add_multiple_of_row(self, i: int, j: int, s) -> HtmlFragment:
"""Add s times row j to row i. The operation is done in place."""
return HtmlFragment(''.join([r'\[',
self._latex_(),
self._format_row_operations(self._add_multiple_of_row(i, j, s)),
r'\rightarrow',
self._latex_(),
r'\]']))
def col_expansion(self, i: int) -> HtmlFragment:
"""Laplace expansion on i-th column."""
output = list()
output.append(r'\[')
for j in range(self.M.nrows()):
if j > 0:
output.append('+')
output.append(r'(-1)^{' f'{j+1} + {i+1}' r'}\cdot')
output.append(f'({self.M[j, i]})'
r'\cdot')
N = self.M[[k for k in range(self.M.nrows()) if k != j],
[k for k in range(self.M.ncols()) if k != i]]
output.append(IMatrix(N).as_determinant()._latex_())
output.append(r'\]')
return HtmlFragment(''.join(output))
def my_run_simplex_method(self):
output = []
while not self.is_optimal():
self.pivots += 1
if self.entering() is None:
self.enter(self.pivot_select_entering())
if self.leaving() is None:
if self.possible_leaving():
self.leave(self.pivot_select_leaving())
output.append(self._html_())
if self.leaving() is None:
output.append("The problem is unbounded in $()$ direction.".format(
latex(self.entering())))
break
output.append(self._preupdate_output("primal"))
self.update()
if self.is_optimal():
output.append(self._html_())
return HtmlFragment("\n".join(output))
def to_reduced_form(self):
"""Transform self to the reduced echelon form of self."""
output = list()
for changed_row in range(1, self.M.nrows()):
operations = {i: r'\ ' for i in range(self.M.nrows())}
unchanged = self._latex_()
for row in range(0, changed_row):
factor = -self.M[row][changed_row]
operations.update(self._add_multiple_of_row(row, changed_row, factor))
output.append(r'\[')
output.append(unchanged)
output.append(self._format_row_operations(operations))
output.append(r'\rightarrow')
output.append(self._latex_())
output.append(r'\]')
return HtmlFragment('\n'.join(output))
def _html_(self):
r"""
HTML representation of a table.
Strings of html will be parsed for math inside dollar and
double-dollar signs. 2D graphics will be displayed in the
cells. Expressions will be latexed.
The ``align`` option for tables is ignored in HTML
output. Specifying ``header_column=True`` may not have any
visible effect in the Sage notebook, depending on the version
of the notebook.
OUTPUT:
A :class:`~sage.misc.html.HtmlFragment` instance.
EXAMPLES::
sage: T = table([[r'$\sin(x)$', '$x$', 'text'], [1,34342,3], [identity_matrix(2),5,6]])
sage: T._html_()
<div.../div>
sage: print(T._html_())
<div class="notruncate">
<table class="table_form">
<tbody>
<tr class ="row-a">
<td><script type="math/tex">\sin(x)</script></td>
<td><script type="math/tex">x</script></td>
<td>text</td>
</tr>
<tr class ="row-b">
<td><script type="math/tex">1</script></td>
<td><script type="math/tex">34342</script></td>
<td><script type="math/tex">3</script></td>
</tr>
<tr class ="row-a">
<td><script type="math/tex">\left(\begin{array}{rr}
1 & 0 \\
0 & 1
\end{array}\right)</script></td>
<td><script type="math/tex">5</script></td>
<td><script type="math/tex">6</script></td>
</tr>
</tbody>
</table>
</div>
Note that calling ``html(table(...))`` has the same effect as
calling ``table(...)._html_()``::
sage: T = table([["$x$", r"$\sin(x)$"]] + [(x,n(sin(x), digits=2)) for x in [0..3]], header_row=True, frame=True)
sage: T
+-----+-----------+
| $x$ | $\sin(x)$ |
+=====+===========+
| 0 | 0.00 |
+-----+-----------+
| 1 | 0.84 |
+-----+-----------+
| 2 | 0.91 |
+-----+-----------+
| 3 | 0.14 |
+-----+-----------+
sage: print(html(T))
<div class="notruncate">
<table border="1" class="table_form">
<tbody>
<tr>
<th><script type="math/tex">x</script></th>
<th><script type="math/tex">\sin(x)</script></th>
</tr>
<tr class ="row-a">
<td><script type="math/tex">0</script></td>
<td><script type="math/tex">0.00</script></td>
</tr>
<tr class ="row-b">
<td><script type="math/tex">1</script></td>
<td><script type="math/tex">0.84</script></td>
</tr>
<tr class ="row-a">
<td><script type="math/tex">2</script></td>
<td><script type="math/tex">0.91</script></td>
</tr>
<tr class ="row-b">
<td><script type="math/tex">3</script></td>
<td><script type="math/tex">0.14</script></td>
</tr>
</tbody>
</table>
</div>
"""
from itertools import cycle
rows = self._rows
header_row = self._options['header_row']
if self._options['frame']:
frame = 'border="1"'
else:
frame = ''
s = StringIO()
if rows:
s.writelines([
# If the table has < 100 rows, don't truncate the output in the notebook
'<div class="notruncate">\n'
if len(rows) <= 100 else '<div class="truncate">',
'<table {} class="table_form">\n'.format(frame),
'<tbody>\n',
])
# First row:
if header_row:
s.write('<tr>\n')
self._html_table_row(s, rows[0], header=header_row)
s.write('</tr>\n')
rows = rows[1:]
# Other rows:
for row_class, row in zip(cycle(["row-a", "row-b"]), rows):
s.write('<tr class ="{}">\n'.format(row_class))
self._html_table_row(s, row, header=False)
s.write('</tr>\n')
s.write('</tbody>\n</table>\n</div>')
from sage.misc.html import HtmlFragment
return HtmlFragment(s.getvalue())
def to_echelon_form(self) -> HtmlFragment:
"""Transform self to the echelon form of self."""
output = list()
# Gaussian elimination algorithm is derived from
# https://ask.sagemath.org/question/8840/how-to-show-the-steps-of-gauss-method/
col = 0 # all cols before this are already done
for row in range(0, self.M.nrows()):
# Need to swap in a nonzero entry from below
while col < self.M.ncols() and self.M[row][col] == 0:
for i in self.M.nonzero_positions_in_column(col):
if i > row:
output.append(r'\[')
output.append(self._latex_())
output.append(self._format_row_operations(self._swap_rows(row, i)))
output.append(r'\rightarrow')
output.append(self._latex_())
output.append(r'\]')
break
else:
col += 1
if col >= self.M.ncols() - self.separate:
break
# Now guaranteed M[row][col] != 0
if self.M[row][col] != 1:
if not is_invertible(self.M[row][col]):
output.append(f'<br>Przerywam eliminację bo nie wiem, czy wyrażenie '
f'${sage.all.latex(self.M[row][col])}$ jest niezerowe.')
break
else:
output.append(r'\[')
output.append(self._latex_())
output.append(self._format_row_operations(self._rescale_row(row, 1 / self.M[row][col])))
output.append(r'\rightarrow')
output.append(self._latex_())
output.append(r'\]')
change_flag = False
unchanged = self._latex_()
operations = dict()
for changed_row in range(row + 1, self.M.nrows()):
if self.M[changed_row][col] != 0:
change_flag = True
factor = -1 * self.M[changed_row][col] / self.M[row][col]
operations.update(self._add_multiple_of_row(changed_row, row, factor))
if change_flag:
output.append(r'\[')
output.append(unchanged)
output.append(self._format_row_operations(operations))
output.append(r'\rightarrow')
output.append(self._latex_())
output.append(r'\]')
col += 1
return HtmlFragment('\n'.join(output))
