Friday, 17 June 2016

Code Cost: Write less code

Based on @UmerMansoor 
Not too long ago, I sat down to ‘clean up’ a project that I inherited. I was given the reins of the refactoring efforts because the project has had several bugs in production. It was stuck in a vicious cycle where fixing old bugs would introduce new ones.
So I dived into the source code one weekend and the problem soon became evident: the project was a big, hairy mess. I use the word big because there was lots of unnecessary, redundant and tightly coupled code. Byhairy mess, I don’t mean that the code looked amateur or was full of shortcuts. In fact, the problem was quite the opposite. There was too much magic and everywhere I looked, I saw clever and grandiose design practices that had no relationship with the actual problem that the project was built to solve. Things like reflection, aspect oriented programming, custom annotations were all present. The project was an over-engineered beast. To put it into perspective, after the refactoring was over, the project was reduced to less than half of its original size.

Thursday, 9 June 2016

BioDocker Announcement

The BioDocker web page is out: biodocker.org

The Documentation: biodocker.org/docs

The GitHub: github.com/BioDocker/

Registry: hub.docker.com/u/biodckr/

How to estimate and compute the isoelectric point of peptides and proteins?

By +Yasset Perez-Riverol and +Enrique Audain :

Isoelectric point (pI) can be defined as the point of singularity in a titration curve, corresponding to the solution pH value at which the net overall surface charge is equal to zero. Currently, there are available different modern analytical biochemistry and proteomics methods depend on the isoelectric point as a principal feature for protein and peptide characterization. Peptide/Protein fractionation according to their pI is widely used in current proteomics sample preparation procedures previous to the LC-MS/MS analysis. The experimental pI records generated by pI-based fractionation procedures are a valuable information to validate the confidence of the identifications, to remove false positive and and could be used to re-compute peptide/protein posterior error probabilities in MS-based proteomics experiments. 

Theses approaches require an accurate  theoretical prediction of pI. Even thought there are several tools/methods to predict the isoelectric point, it remains hard to define beforehand what methods perform well on a specific dataset.  

We believe that the best way to compute the isoelectric point (pI) is to have a complete package with most of the algorithms and methods in the state of the art that can do the job for you [2]. We recently developed an R package (pIR) to compute isoelectric point using long-standing and novels pI methods that can be grouped in three main categories : a) iterative, b) Bjellvist-based methods and c) machine learning methods. In addition, pIR also offers a statistical and graphical framework to evaluate the performance of each method and its capability to “detect” outliers (those peptides/protein with theoretical pI biased from experimental value) in a high-throughput environment.

First lets install the package:

First, we need to install devtools:
install.packages("devtools")
library(devtools)
Then we just call:
install_github("ypriverol/pIR")
library(pIR)