Subversion Repositories tcp_socket

#!/usr/bin/env python

import subprocess

import atexit

from math import pi

try:

    from matplotlib import pyplot

except ImportError:

    print "You need matplotlib to run this script!"

    exit(0)

children = []

def cleanup():

    for child in children:

        print "Terminating child process"

        child.terminate()

atexit.register(cleanup)

def run_c(file_name):

    process = subprocess.Popen(["../c2verilog", "iverilog", "run", str(file_name)])

    children.append(process)

    process.wait()

    children.remove(process)

def test():

    run_c("sqrt.c")

    x = [float(i) for i in open("x")]

    sqrt_x = [float(i) for i in open("sqrt_x")]

    pyplot.plot(x, sqrt_x)

    pyplot.xlim(0, 10.1)

    pyplot.title("Square Root of x")

    pyplot.xlabel("x")

    pyplot.ylabel("$\\sqrt{x}$")

    pyplot.savefig("../docs/source/examples/images/example_1.png")

    pyplot.show()

def indent(lines):

    return "\n    ".join(lines.splitlines())

def generate_docs():

    documentation = """

Calculate Square Root using Newton's Method

-------------------------------------------

In this example, we calculate the sqrt of a number using `Newton's method

<http://en.wikipedia.org/wiki/Newton's_method#Square_root_of_a_number>`_.

The problem of finding the square root can be expressed as:

.. math::

     n = x^2

Which can be rearranged as:

.. math::

     f(x) = x^2 - n

Using Newton's method, we can find numerically the approximate point at which

:math:`f(x) = 0`. Repeated applications of the following expression yield

increasingly accurate approximations of the Square root:

.. math::

    f(x_k) = x_{k-1} - \\frac{{x_{k-1}}^2 - n}{2x_{k-1}}

Turning this into a practical solution, the following code calculates the square

root of a floating point number. An initial approximation is refined using

Newton's method until further refinements agree to within a small degree.

.. code-block:: c

    %s

Note that the code isn't entirely robust, and cannot handle special cases such

as Nans, infinities or negative numbers.  A simple test calculates

:math:`\\sqrt{x}` where :math:`-10 < x < 10`.

.. image:: images/example_1.png

"""%indent(open("sqrt.c").read())

    document = open("../docs/source/examples/example_1.rst", "w").write(documentation)

test()

generate_docs()