We have an analysis routine for proteomics data written for IgorPro. One output is a volcano plot . These plots show the fold change in one sample compared to another and plot that against a p-value to estimate how reproducible any changes observed are. This post is not about that software, but on the topic of how we can recreate this plot in R . What steps need to be considered?
A comment from a referee led me to find a method to describe curvature of membranes. This is a quick write-up of our solution. I couldn’t find a solution readily available in Fiji, so I created one using a combination of Fiji for tracing the curvature and IgorPro to do the fitting. If there is any interest I can convert this code into an all-Fiji routine. The code is simple and a gist is available here.
Clathrin is a three-legged protein complex or triskelion that can assemble into lattice-like structures. Inside the cell, this assembly helps to create vesicles: tiny packages of membranes containing proteins and goodies for the cell to use. Incredibly our first view of assembled clathrin was made in the 1960s, with resolution improving steadily since then. The image below shows these improvements.
A short follow-up post. Previously, I looked at how to reproduce a Strava feature that compares performance over similar courses. With a few modifications to the code, I was able to analyse a much larger dataset of cycling performance on similar courses. Two courses with the highest number of tracks are shown below. I cycle these courses all the time. Well, I did until the pandemic struck.
One of several features that Strava put behind a paywall was the ability to compare performance on similar courses. I miss this comparison tool and wondered how hard it would be to code my own. I would love to… but I don’t subscribe This post is a walkthrough of how I approached the problem. The code is available here. It uses the trackeR library in R to convert the GPX tracks to a huge dataframe. This is then processed by IgorPro.
A short tech-tip this week. How can you find a line of code somewhere on your computer? I often find that I need to write a line of code and I can’t remember the exact syntax. To add to the frustration, I can remember writing a similar line before, but can’t remember in which file it was (or for what project, or even when it might’ve been). How can I quickly track that line down? Today I needed to write a LoadWave command in Igor.
A quick post this week. I write “this week” in an attempt to convince regular readers that weekly posting will continue. I noticed that J. Cell Sci. give download metrics for their papers and that these downloads are categorised into abstract, full-text and PDF. I was interested in how one of my papers performed.
On a whim a posted a plot on Twitter. It shows a marathon training schedule. This post explains the story behind the graph. I downloaded a few different 17-week marathon training schedules. Most were in imperial measurement and/or were written for time at a certain pace, e.g. 30 min Easy Run etc.
I really dislike being asked “how big is your lab?”. The question usually arises at scientific meetings when you are chatting to someone during a break. Small talk can lead to some banal questions being asked, and that’s fine, but when this question is asked seriously, the person asking really just wants to compare themselves to you in some way.
It has been a long time since I wrote a book review. A few months ago I read on IgorExchange that Martin Schmid had written a book about programming Igor. I snapped up a copy. I’m a competent Igor programmer but I was hoping that this book would be useful for lab members that want to learn. Learning Igor – like most IDEs or programming languages – is tough going.