Pweave Basics

Pweave documents

A Pweave input document contains documentation and code separated with special markup. Pweave supports several input formats for different purposes. All of the source formats produce identical output for code. You need to tell the input format to Pweave using -i command line option.

Code chunk formats

markdown

Pweave can run code from fenced markdown python code blocks. It is recommended to .pmd file extension.

Sample code block syntax:

```python
x = np.linspace(0, 2*np.pi)
plt.plot(x, np.sin(x))
```

Example document: FIR_designp.pmd and output: FIR_designp.html compiled running:

pweave -f md2html FIR_designp.pmd

All of the following are valid ways to define a code chunk:

```python
```{python}
```{.python}

You can define chunk options:

```{python, caption = "Some figure"}
```python, echo=False

noweb

Noweb syntax for defining code chunks has been adopted from Sweave.

Code chunk starts with a line marked with <<>>= or <<options>>= and end with line marked with @. The code between the start and end markers is executed and the output is captured to the output document.

Example: A code chunk that saves and displays a 12 cm wide image and hides the source code:

<<fig = True, width = '12 cm', echo = False>>=
from pylab import *
plot(arange(10))
show()
@

Documentation chunk

The rest of the document is just copied to ouput and can be written with several different markup languages. See formats page for a list of supported output formats.

Inline code

Pweave supports evaluating inline code in documentation chunks using <% %> (code will be evaluated in place) and <%= %> (result of expression will be printed) tags. Inline code will not be included in weaved document.

New in version 0.2.

Terminology

Source document

Contains a mixture of documentation and code chunks. Pweave will evaluate the code and leave the documentation chunks as they are. The documentation chunks can be written either with reST,Latex or Pandoc markdown. The source document is processed using Pweave, which gives us the formatted output document.

Weaved document

Is produced by Pweave from the source document. Contains the documentation, original code, the captured outputof the code and optionally captured matplotlib figures.

Source code

Is produced by Pweave from the source document. Contains the source code extracted from the code chunks.