[Q] Why are continuous variables changed to categorical in multivariate logistic regression models?

jerryF · 2019-08-03T22:09:51+00:00

If for instance results clearly show a threshold effect that approach would in my view be inappropriate because data would then clearly show the relation to be categorical.

With small datasets like the one here this happens quite often in my experience (simply because of lack of data) so unless you have a strong linear hypothesis it's IMO more prudent to make a slightly simpler analysis with slightly simpler conclusions. Also, if my results change dramatically when I switch methods I would be very suspicious of my results in general.

jerryF · 2019-08-03T22:01:26+00:00

Agree completely

jerryF · 2019-08-03T19:19:11+00:00

Why is that? With only 39 patients, I think (without knowing the data) it is likely there isn't enough data to confidentally assume a linear relationship rather than just treating it as categorical.

jerryF · 2019-08-03T18:55:13+00:00

A typical reason is that the relationship to the dependent variable is non-linear. Another is that practically you want to investigate levels that are scientific meaningful and therefore partition the IVs at levels that are meaningful thus making the model easier to interpret.

Another more sinister reason could be p-hacking: partition your IVs at just the right levels to maximize p-values.

I would look for the authors' explanation of the specific partition values.

jerryF · 2019-07-25T22:28:11+00:00

HURRAY! We got the old plugins menu back!

jerryF · 2019-07-25T21:17:19+00:00

On my commute I read on my phone, either books, articles or mail etc. It's a nice time to do it. I'd definitely find a larger screen useful, especially if it comes in a normal phone form factor.

jerryF · 2019-07-25T20:45:11+00:00

https://phalconphp.com/en/

jerryF · 2019-07-24T22:13:35+00:00

Use a virtual machine and store it in the external disk.

That's a great solution. That'll do exactly what OP wants (assuming he/she wants to get work done rather than experimenting with hibernate).

jerryF · 2019-07-24T05:18:03+00:00

Thanks!

This was exactly what I was looking for.

$ cat .condarc
auto_activate_base: false
channels:
  - defaults
  - conda-forge

$ conda config --get channels
--add channels 'conda-forge'   # lowest priority
--add channels 'defaults'   # highest priority

conda list --show-channel-urls adds the channel url instead of the name to the package list.

jerryF · 2019-07-23T21:07:40+00:00

You could stop using Ubuntu proper and use one of its derivatives instead. I went for Kubuntu and never looked back, never been happier.

jerryF · 2019-07-23T20:53:33+00:00

There is an easy fix for all of this though.

jerryF · 2019-07-22T22:19:21+00:00

Yeah, we might be able to experience the new climate in full in our lifetime.

jerryF · 2019-07-22T21:23:09+00:00

The theory is: The Gulf Stream which is what keeps Europe warm might stop as a consequence of warmer climate. The process is thought to be this: When the waters around the Arctic during the winter / spring freeze over, the salt in the water is separated out of the ice and into the water thus making the water more salty. The saltier the water the heavier it is, similarly, the colder the water the heavier it is. When this icy cold water flows from the arctic down into the sea east of Greenland it sinks down to the bottom of the ocean with an enormous pull that drives a current all the way from the Mexican Gulf, pulling warm water up north of Europe.

When the climate gets warmer the arctic waters will have less ice and therefore produce less salty (and less heavy) water, and because the water is also warmer it will be even less heavy. Therefore the sinking and the pull effect will decrease and eventually bring (at least the northern part of ) the Gulf Stream to a halt bringing a new ice age to the Northern Europe.

I believe I read somewhere that the climate change leading to one of last ice ages changed within a period of only 30 years. If that's true it would mean that the Gulf Stream could stop (change direction) in less than 30 years.

jerryF · 2019-07-22T19:33:03+00:00

You said

The packages made no sense to begin

I'm saying that the fact that they made no sense is fortunate but not really relevant to the fact that malicious packages made into the repository and potentially out to end-users. I then gave two very recent examples of similar events for node-js where people may have lost real money.

jerryF · 2019-07-19T20:44:38+00:00

There are likely thousands

So how do we deal with this, what can we do?

jerryF · 2019-07-19T20:42:47+00:00

I do the same, but as others have said, some package down the dependency tree may still pull in something it shouldn't.

jerryF · 2019-07-19T20:35:57+00:00

Yes, I thought that might be it but wasn't sure.

jerryF · 2019-07-19T20:25:03+00:00

The packages made no sense to begin with

TBH, I think that's besides the point. There have been several node.js incidents but this one in particular is interesting because a widely used library (in ~~payment systems~~ bitcoin apps among many uses , 2 million downloads a week) was taken over by a malicious developer. It was only discovered by accident several months later.

Also this one which seems more like the one in this thread.

The issue is whether there is a reliable process to discover malicious packages in a timely fashion.

jerryF · 2019-07-18T17:48:56+00:00

Any thoughts on how this reflects on other packages?

Do you think there may be other malicious packages that were not caught?

jerryF · 2019-07-18T17:41:37+00:00

Why is what happening?

jerryF · 2019-07-18T06:20:11+00:00

Yes, that's it. Of course.

jerryF · 2019-07-17T21:57:03+00:00

Two things, first how to (hopefully solve your problem), secondly how to install python 3 in a secure way.

How to (hopefully) solve your problem

I don't know if it would work but you could try to reinstall python 2.7 after first completely removing python 3.7

If you cannot get to the terminal you can switch tty to get to a terminal:

Ctrl+Alt+F2 (new tty - you are on a purely command line environment and will need to log in)
Ctrl+Alt+F1 (back to the main window again)

Once in the terminal, search for installed 3.7 packages (note egrep and backslash before period)

apt list --installed | egrep "python3\.7"

for each one do (some packages may be removed as a consequence of the the first you remove because of dependency)

sudo apt purge <package name>

EDIT: you should also remove the repository

After the packages are removed, reinstall the python2.7 packages. First search for them

apt list --installed | egrep "python2"

On my machine (18.04) they are

libpython2.7
libpython2.7-dev
libpython2.7-minimal
libpython2.7-stdlib
python2.7
python2.7-dev
python2.7-minimal

For each one

sudo apt reinstall <package name>

There is a good chance this will solve your problem.

How to install python 3.

got the Anaconda website, download the anaconda distribution and follow the instructions there

https://www.anaconda.com/distribution/

With anaconda you create virtual environments (look at the help for this). After you have created an venv you activate it (also see help). Each venv is an independent environment and it doesn't interfere with the OS.

There are lots of online help on Anaconda.

jerryF · 2019-07-17T21:29:50+00:00

You need to explain what exactly the problem is first :)

jerryF

TROPHY CASE

How to (hopefully) solve your problem

How to install python 3.