misc/numworks: add echelon script for numworks.

This commit is contained in:
Kyle Isom 2018-06-04 22:17:09 -07:00
parent f342fc91db
commit c5401e5128
2 changed files with 118 additions and 0 deletions

29
misc/numworks/README.md Normal file
View File

@ -0,0 +1,29 @@
numworks
========
Various programs for my [numworks](https://numworks.com/) calculator.
Echelon
-------
This is a tool to help explore transformations to convert a matrix to
row echelon form.
```python
>>> from echelon import *
>>> m = EMatrix([[1, 1, 1], [3, 2, 1], [2, 1, 2]], [15, 28, 23])
>>> print(m)
1 1 1 -> 15
3 2 1 -> 28
2 1 2 -> 23
>>> m.add(-3, 0, 1)
>>> m.add(-2, 0, 2)
>>> m.scale(-1, 1)
>>> m.add(1, 1, 2)
>>> m.scale(1/2, 2)
>>> print(m)
1 1 1 -> 15
0 1 2 -> 17
0 0 1 -> 5
```

89
misc/numworks/echelon.py Normal file
View File

@ -0,0 +1,89 @@
class EMatrix:
def __init__(self, mat, sol):
self.mat = []
l = -1
for i in range(len(mat)):
tmp = []
if l == -1:
l = len(mat[i])
else:
assert(len(mat[i]) == l)
for j in range(len(mat[i])):
tmp.append(mat[i][j])
self.mat.append(tmp)
assert(len(sol) == l)
self.sol = []
for i in range(len(sol)):
self.sol.append(sol[i])
def copy(self):
mat = []
sol = []
for i in range(len(self.mat)):
tmp = []
for j in range(len(self.mat[i])):
tmp.append(self.mat[i][j])
mat.append(tmp)
for i in range(len(self.sol)):
sol.append(self.sol[i])
return EMatrix(mat, sol)
def add(self, k, r1, r2):
row1 = [v for v in self.mat[r1]]
row2 = self.mat[r2]
for i in range(len(row1)):
row1[i] = k * row1[i]
row2[i] += row1[i]
sol = self.sol[r1] * k
self.mat[r2] = row2
self.sol[r2] += sol
def sub(self, k, r1, r2):
row1 = [v for v in self.mat[r1]]
row2 = self.mat[r2]
for i in range(len(row1)):
row1[i] = k * row1[i]
row2[i] -= row1[i]
sol = self.sol[r1] * k
self.mat[r2] = row2
self.sol[r2] -= sol
def scale(self, k, r):
for i in range(len(self.mat[r])):
self.mat[r][i] *= k
self.sol[r] *= k
def __repr__(self):
return "{}x{} EMatrix".format(len(self.sol), len(self.mat))
def __str__(self):
m = 0
s = ''
for i in range(len(self.mat)):
for j in range(len(self.mat[i])):
m = max(m, len('{:g}'.format(self.mat[i][j])))
for i in range(len(self.sol)):
m = max(m, len('{:g}'.format(self.sol[i])))
fmt = '{' + ':>{}g'.format(m) + '}'
for i in range(len(self.mat)):
for j in range(len(self.mat[i])):
s += fmt.format(self.mat[i][j])
s += ' '
s += ' -> ' + fmt.format(self.sol[i]) + '\n'
return s