[BioC] namespace and other developer tools

[James W. MacDonald]

Hi Naomi,

Naomi Altman wrote:
> I have also been foiled by the sophistication of Bioconductor code.
> 
> Is there a manual that explains namespace and other code-hiding tools 
> (.e.g generic functions) that would provide some guidance.
> The beauty of R is that I can hack - when I can find the code.
> 

I don't know of any manual that covers the topic, but there are only a 
few things you really need to know to find things.

____________________
NAMESPACE
____________________

General description:
http://en.wikipedia.org/wiki/Namespace_%28computer_science%29

R manual info:
http://cran.r-project.org/doc/manuals/R-exts.html
See section 1.6

To find/see/use methods in a namespace
?methods
?'::'

For example:

 > t.test
function (x, ...)
UseMethod("t.test")
<environment: namespace:stats>

Not very useful.

 > methods("t.test")
[1] t.test.default* t.test.formula*

    Non-visible functions are asterisked

Getting closer.

 > stats:::t.test.default

Will show the function.

____________________
S4 methods
____________________

http://www.bioconductor.org/developers/progRef/S4Objects.pdf

Finding things:

?showMethods

In particular the includeDefs argument.

For example:

 > library(GOstats)
 > hyperGTest
standardGeneric for "hyperGTest" defined from package "Category"
   defined with value class: "HyperGResultBase"

function (p)
.valueClassTest(standardGeneric("hyperGTest"), "HyperGResultBase",
     "hyperGTest")
<environment: 0x039c1314>
Methods may be defined for arguments: p

Not very helpful.

 > showMethods("hyperGTest", includeDefs=T)

Will show the function(s)

As many BioC packages use both S4 methods and a namespace, you often 
need to use a combination of the two in order to find things.

Best,

Jim


> Thanks,
> Naomi
> 

-- 
James W. MacDonald, M.S.
Biostatistician
Affymetrix and cDNA Microarray Core
University of Michigan Cancer Center
1500 E. Medical Center Drive
7410 CCGC
Ann Arbor MI 48109
734-647-5623


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