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py2tex.py
"""
Module for IPython to display code with TeX representation.
This makes for example the following workflow possible:
.. sourcecode:: ipython
In [1]: %load_ext py2tex
In [2]: from math import *
In [3]: %tex (1+sqrt(5))/2
(1+sqrt(5))/2 = 1.618
In [4]: %%tex a = 1.0
...: b=3.0
...: c = sqrt(a**2+b**2)
...:
a = 1.0
b=3.0
c = sqrt(a**2+b**2) = 3.162
In [5]: %texformat %.3e
In [6]: %tex e**10
e**10 = 2.203 \cdot 10^{4}
In [7]: %texnr c = sqrt(a**2+b**2)
c = sqrt(a**2+b**2)
When IPython TeX rendering is enabled, the results are displayed with TeX !!!
Usage
=====
The following magic commands are provided:
``%tex``
One line TeX conversion with result output.
``%%tex``
Multi line TeX conversion with result output.
``%texnr``
One line TeX conversion without result output.
``%%texnr``
Multi line TeX conversion without result output.
``%texformat``
Set the output format. (e.g. %.3f)
Notes
=====
- Only true mathematical lines are supported for now
- Usage of underscores in variable names will result in subscript.
First _ will be subscript, all other _ will be converted to a ,
- greek letters as variable name are converted to their TeX equivalent
- Usage of the Unum class for unit-ware calculations is supported.
(https://bitbucket.org/kiv/unum/src)
- when unum objects are used, %%tex detects when the expression must be printed
eg. v = 10*m/s is not displayed like v = 10*m/s = 10 m/s as in previous versions
Version history
===============
release 0.2:
- units in expressions are not displayed with italic font
- variable are always italic font
- %%tex knows when the expression is an assignment with units only
release 0.1:
- initial version
"""
import ast
from IPython.core.display import Latex
from IPython.core.magic import (Magics, magics_class, line_magic,
cell_magic, line_cell_magic)
from IPython.core.displaypub import publish_display_data
import re
import unum #
#-----------------------------------------------------------------------------
#Version: 0.2
#
#License:
# All GPLv3 except the class LatexVisitor which is cc by-sa 3.0 as it is based
# upon a snippet from stackoverflow (http://creativecommons.org/licenses/by-sa/3.0/)
#
#Hosted as a Gist:
# https://gist.github.com/4032651
#
#Author:
# Beke, J.
#-----------------------------------------------------------------------------
@magics_class
class PrettyPrint(Magics):
"""Defines IPython magic function for LaTeX output of simple expressions"""
outputFormat = "%.3f"
greekLetters = {'Alpha': '\\Alpha',
'Beta': '\\Beta',
'Chi': '\\Chi',
'Delta': '\\Delta',
'Epsilon': '\\Epsilon',
'Eta': '\\Eta',
'Gamma': '\\Gamma',
'Iota': '\\Iota',
'Kappa': '\\Kappa',
'Lambda': '\\Lambda',
'Mu': '\\Mu',
'Nu': '\\Nu',
'Omega': '\\Omega',
'Phi': '\\Phi',
'Pi': '\\Pi',
'Psi': '\\Psi',
'Rho': '\\Rho',
'Sigma': '\\Sigma',
'Tau': '\\Tau',
'Theta': '\\Theta',
'Upsilon': '\\Upsilon',
'Xi': '\\Xi',
'Zeta': '\\Zeta',
'alpha': '\\alpha',
'beta': '\\beta',
'chi': '\\chi',
'delta': '\\delta',
'epsilon': '\\epsilon',
'eta': '\\eta',
'gamma': '\\gamma',
'varphi': '\\varphi',
'iota': '\\iota',
'kappa': '\\kappa',
'lambda': '\\lambda',
'mu': '\\mu',
'nu': '\\nu',
'omega': '\\omega',
'phi': '\\phi',
'pi': '\\pi',
'psi': '\\psi',
'rho': '\\rho',
'sigma': '\\sigma',
'tau': '\\tau',
'theta': '\\theta',
'upsilon': '\\upsilon',
'varepsilon': '\\varepsilon',
'varkappa': '\\varkappa',
'varphi': '\\varphi',
'varpi': '\\varpi',
'varrho': '\\varrho',
'varsigma': '\\varsigma',
'vartheta': '\\vartheta',
'xi': '\\xi',
'zeta': '\\zeta'}
def __init__(self, shell):
super(PrettyPrint, self).__init__(shell)
@line_cell_magic
def tex(self, line, cell= None):
"""Cell and line magic %tex"""
#always do first line
self.doLine(line)
#in case of cellmagic (with %%tex)
if not (cell is None):
for cline in cell.split("\n"):
if len(cline)>0:
self.doLine(cline)
@line_cell_magic
def texnr(self, line, cell= None):
"""Cell and line magic %texnr"""
#always do first line
self.doLine(line,True)
#in case of cellmagic (with %%tex)
if not (cell is None):
for cline in cell.split("\n"):
if len(cline)>0:
self.doLine(cline,True)
@line_magic
def texformat(self, line):
"""cell magic to set the result format string"""
arg = line.strip(" \t")
try:
temp = arg % 3.1415
self.outputFormat = line.strip(" \t")
except ValueError:
raise ValueError(arg + " is not supported")
def doLine(self,line,no_result = False):
"""Method to convert and print one line
"""
#check for assignment
i = line.find("=")
if i<0 or line[i+1]=='=':
# no assignment : print expression = result
result = self.shell.ev(line)
publish_display_data('PrettyPrint',
{'text/latex': "$$"+self.py2tex(line)+" = "+self.numericToString(result)+"$$",
'text/plain': line+" = "+self.numericToString(result)})
else:
# expression was assignment
variable = line[:i].strip()
expression = line[i+1:].strip()
result = self.shell.ev(expression)
self.shell.push({variable: result})
temp = re.findall('[-+]?\d*\.\d+[eE][-+]?\d+|[-+]?\d*\.\d+|[-+]?\d+', expression.strip())
try:
temp=float(expression)
# assignment: variable = number
publish_display_data('PrettyPrint',
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.py2tex(expression)+"$$",
'text/plain': line})
except ValueError:
if no_result:
# assignment: variable = expression
publish_display_data('PrettyPrint',
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.py2tex(expression)+"$$",
'text/plain': line})
else:
# assignment: variable = expression = number
# unit is always an expression so test first
if self.isUnumAssignment(expression):
#unit assignment, print only result
publish_display_data('PrettyPrint',
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.numericToString(self.shell.ev(expression))+"$$",
'text/plain': line+" = "+self.numericToString(self.shell.ev(variable.strip()))})
else:
# assignment: variable = expression = number
publish_display_data('PrettyPrint',
{'text/latex': "$$"+self.parseVariable(variable.strip())+" = "+self.py2tex(expression)+" = "+self.numericToString(self.shell.ev(variable.strip()))+"$$",
'text/plain': line+" = "+self.numericToString(self.shell.ev(variable.strip()))})
def numericToString(self, number):
"""Convert a number to the defined string representation"""
if type(number) == unum.Unum:
a = self.outputFormat % number._value
unit = "\\;\\:%s" % self.prettyUnumUnit(number) #number.strUnit()[1:-1]
else:
a = self.outputFormat % number
unit = ''
a = a.split("e")
if len(a)==1:
return a[0] + unit
else:
if int(a[1]) != 0:
return "%s \\cdot 10^{%s} %s" % (a[0], int(a[1]), unit)
else:
return a[0] + unit
def py2tex(self, expr):
"""Actual expression to TeX conversion"""
pt = ast.parse(expr)
return LatexVisitor().visit(pt.body[0].value)
def parseVariable(self, name):
"""Convert a variable to greek letters and parse the _ to subscript or comma"""
#parse greek letters
name = name.split("_")
for i in range(len(name)):
if self.greekLetters.has_key(name[i]):
name[i] = self.greekLetters[name[i]]
#first part as mbox
#if name[0].find("\\") < 0:
# name[0] = "\\mbox{%s}" % name[0]
#parse underscore and comma
if len(name)>1:
return name[0]+"_{"+','.join(name[1:])+"}"
return name[0]
def prettyUnumUnit(self,unum):
"""Pretty print a Unum unit object"""
n = ''
d = ''
for name,power in sorted(unum._unit.items()):
if power < 0:
if power ==-1:
d += "$\\mbox{%s}" % (name)
else:
d += "$\\mbox{%s}^{%d}" % (name, power*-1)
else:
if power == 1:
n += "$\\mbox{%s}" % (name)
else:
n += "$\\mbox{%s}^{%d}" % (name, power)
if n=='':
n ='1'
n=n.strip("$").replace("$","\\cdot")
d=d.strip("$").replace("$","\\cdot")
if d =='':
if n=='1':
return ''
else:
return n
else:
return n+"/"+d
def isUnumAssignment(self,expression):
""" Check if the expression is an Unum assignment """
pos = expression.find("*")
if pos>=1:
number = expression[0:pos]
unit = expression[pos+1:]
# test if number is really a number
try:
float(number)
except ValueError:
# no unit assignment
return False
# try if unit part evaluated is of type unum and _value=1
result = self.shell.ev(unit)
if type(result)==unum.Unum:
if result._value!=1:
# no unit assignment
return False
else:
# no unit assignment
return False
else:
# no * so no unit
return False
# if reached this statement, must be unum assignment
return True
class LatexVisitor(ast.NodeVisitor):
# based on source: http://stackoverflow.com/questions/3867028/converting-a-python-numeric-expression-to-latex
greekLetters = PrettyPrint.greekLetters
functions = {'arccos': '\\arccos',
'arcsin': '\\arcsin',
'arctan': '\\arctan',
'cos': '\\cos',
'cosh': '\\cosh',
'cot': '\\cot',
'coth': '\\coth',
'csc': '\\csc',
'ln': '\\ln',
'log': '\\log',
'max': '\\max',
'min': '\\min',
'sec': '\\sec',
'sin': '\\sin',
'sinh': '\\sinh',
'tan': '\\tan',
'tanh': '\\tanh'}
def prec(self, n):
return getattr(self, 'prec_'+n.__class__.__name__, getattr(self, 'generic_prec'))(n)
def visit_Call(self, n):
func = self.visit(n.func)
args = ', '.join(map(self.visit, n.args))
if func == 'sqrt':
return '\sqrt{%s}' % args
else:
# parse know LaTeX functions
if self.functions.has_key(func):
return r'%s\left(%s\right)' % (self.functions[func], args)
else:
return r'\mbox{%s}\left(%s\right)' % (func, args)
def prec_Call(self, n):
return 1000
def visit_Name(self, n):
#test if unum
result = get_ipython().ev(n.id)
if type(result) == unum.Unum:
if result._value==1:
return "\\mbox{%s}" % n.id
#parse greek letters
name = n.id.split("_")
for i in range(len(name)):
if self.greekLetters.has_key(name[i]):
name[i] = self.greekLetters[name[i]]
#parse underscore and comma
if len(name)>1:
return name[0]+"_{"+','.join(name[1:])+"}"
return name[0]
def prec_Name(self, n):
return 1000
def visit_UnaryOp(self, n):
if self.prec(n.op) > self.prec(n.operand):
return r'%s \left(%s\right)' % (self.visit(n.op), self.visit(n.operand))
else:
return r'%s %s' % (self.visit(n.op), self.visit(n.operand))
def prec_UnaryOp(self, n):
return self.prec(n.op)
def visit_BinOp(self, n):
if self.prec(n.op) > self.prec(n.left):
left = r'\left(%s\right)' % self.visit(n.left)
else:
left = self.visit(n.left)
if self.prec(n.op) > self.prec(n.right):
right = r'\left(%s\right)' % self.visit(n.right)
else:
right = self.visit(n.right)
if isinstance(n.op, ast.Div):
return r'\frac{%s}{%s}' % (self.visit(n.left), self.visit(n.right))
elif isinstance(n.op, ast.FloorDiv):
return r'\left\lfloor\frac{%s}{%s}\right\rfloor' % (self.visit(n.left), self.visit(n.right))
elif isinstance(n.op, ast.Pow):
return r'%s^{%s}' % (left, self.visit(n.right))
else:
return r'%s %s %s' % (left, self.visit(n.op), right)
def prec_BinOp(self, n):
return self.prec(n.op)
def visit_Sub(self, n):
return '-'
def prec_Sub(self, n):
return 300
def visit_Add(self, n):
return '+'
def prec_Add(self, n):
return 300
def visit_Mult(self, n):
return '\\cdot'
def prec_Mult(self, n):
return 400
def visit_Mod(self, n):
return '\\bmod'
def prec_Mod(self, n):
return 500
def prec_Pow(self, n):
return 700
def prec_Div(self, n):
return 400
def prec_FloorDiv(self, n):
return 400
def visit_LShift(self, n):
return '\\mbox{shiftLeft}'
def visit_RShift(self, n):
return '\\mbox{shiftRight}'
def visit_BitOr(self, n):
return '\\mbox{or}'
def visit_BitXor(self, n):
return '\\mbox{xor}'
def visit_BitAnd(self, n):
return '\\mbox{and}'
def visit_Invert(self, n):
return '\\mbox{invert}'
def prec_Invert(self, n):
return 800
def visit_Not(self, n):
return '\\neg'
def prec_Not(self, n):
return 800
def visit_UAdd(self, n):
return '+'
def prec_UAdd(self, n):
return 800
def visit_USub(self, n):
return '-'
def prec_USub(self, n):
return 800
def visit_Num(self, n):
#TODO: convert forms with e03 !
return str(n.n)
def prec_Num(self, n):
return 1000
def generic_visit(self, n):
#walk ???
if isinstance(n, ast.AST):
return r'' % (n.__class__.__name__, ', '.join(map(self.visit, [getattr(n, f) for f in n._fields])))
else:
return str(n)
def generic_prec(self, n):
return 0
def load_ipython_extension(ip):
#register magic to hold state
magicPrettyPrint = PrettyPrint(ip)
ip.register_magics(magicPrettyPrint)
# code below to be uncommented for testing code with
# simple "import py2tex" statement
#ip=get_ipython()
#magicPrettyPrint = PrettyPrint(ip)
#ip.register_magics(magicPrettyPrint)
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