Support RPM to RCF (g force)

[camilogarciabotero]

Hi all,

Thanks for working on this project. I was wondering if there is any way to support the conversion from RPM to RCF (relative centrifuge force) or a.k.a G-force.

It is common to find lab (biology) guide articles and methods that use RCF as the standard unit to describe centrifuge values. Yet, many lab centrifuges display by default the RPM value.

Here is a simple way to represent the unit conversion:

RCF = 1.12 x Radius x (rpm/1000)2

The Radius is conventionally the centrifuge rotor radius, which tends to vary according to the centrifuge's brand and is represented in mm in the aforementioned formula. Here a simple web calculator.

[sharkdp]

So the "proper" way to compute this in a unit-safe way would be via

where is the angular velocity in radians per unit time, which we can compute in insect via

> omega = 2pi * 1000rpm

we can then set the radius:

> r = 100mm

and finally compute RCF in units of 'g' (in insect: gravity) by simply dividing:

> r * omega^2 / gravity

   = 111.824

you could define your own function that takes two arguments:

> rcf(radius, rot_speed) = radius * (2pi rot_speed)^2 / gravity

which could then be used as:

> rcf(100mm, 1000rpm)
   = 111.824

If you are using the terminal version of insect, you can add this to ~/.insectrc. If you are using the web version, there is no convenient way to store this function right now, but you could add this as a bookmark:

https://insect.sh/?q=rcf%28radius%2C+rot_speed%29+%3D+radius+*+%282pi+rot_speed%29%5E2+%2F+gravity

[camilogarciabotero]

Hey @sharkdp

Thanks so much for showing me this way to calculate the RCF via insect. I'll definitely save this to my terminal ~/.insectrc

[camilogarciabotero]

Hi @sharkdp

It's me again. Is the .insectrc feature available? It seems that the .insectrc is not being parsed in the insect env once it starts up.

[sharkdp]

Sorry, I forgot. The feature has not yet been released. You can try to use the latest version from master. I tried to release a new version but have problems with npm (again). I currently don't have the time to look into this further. Any help would be appreciated.

[sharkdp]

It's me again. Is the .insectrc feature available? It seems that the .insectrc is not being parsed in the insect env once it starts up.

it's available now in v5.7.0. let us know if that works.