Bad permission in sudoers files prevents to connect or use sudo

# If you have this message:

sudo: /etc/sudoers.d/rules is world writable

# connect in root 

su

# Then do

chmod 0755 /etc/sudoers.d/rules

To create a root password, do:

sudo passwd root

Do not show a volume in finder (MacOSX)

 From https://www.idownloadblog.com/2016/12/02/how-to-hide-mounted-volumes-from-desktop-finder/

1) Ensure the volume that you want to hide is mounted and visible in the Finder, desktop, or Disk Utility.

2) Make a note of the chosen name of your volume, for example, Time Machine or Storage.

3) Launch Terminal and type the following command, replacing “Drive Name” with the name of your own volume, which you noted earlier (keep the quote marks):

sudo SetFile -a V /Volumes/"Drive Name"

4) Enter your password when prompted.

Note: Install command line developer tools if you’re prompted to do that.

5) In terminal: killall Finder

To revert :

sudo SetFile -a v /Volumes/"Drive Name"

killall Finder

Search a text within the file content in Unix and R

 In UNIX:

grep -rnw '.' -e 'texttosearch'

To search within the current directory '.' or 'path" to search in the path.

The options

-r means "recursive"

-e is the pattern to search for

-n Each output line is preceded by its relative line number in the file, starting at line 1.

-w The expression is searched for as a word (as if surrounded by ‘[[:<:]]’ and ‘[[:>:]]

Do not hesitate to do a man grep to see the dozens of options!

In R, a equivalent using "brut force" (without recursive option) is found in the package HelpersMG (https://CRAN.R-project.org/package=HelpersMG) :

inside(
  text = stop("A text to be searched for is necessary"),
  path = ".",
  pattern = "*\\.R$",
  showallfilenames = FALSE,
  ...,
  fixed = TRUE,
  ignore.case = FALSE
)

Indistinguishable Objects to Distinguishable Boxes

# Indistinguishable Objects to Distinguishable Boxes

# The number of different ways to distribute Nballs indistinguishable balls into

# Nboxes distinguishable boxes is C(Nboxes+Nboxes-1,Nboxes-1).

# For example, 5 balls into 3 boxes can be done in these C(7,2) = 21 ways:

# Number of balls

Nballs <- 10

# Number of boxes

Nboxes <- 3

# The number of different ways to distribute n indistinguishable balls into

# k distinguishable boxes is C(n+k-1,k-1).

# nb<-choose(N+nbjour-1,nbjour-1)=dim(tb)[1]

# divers<-matrix(rep(0, nbjour*nb), ncol=nbjour)

# generate all possible positions of the boundaries

xx <- combn(Nballs+Nboxes-1, Nboxes-1)

# compute the number of balls in each box

a <- cbind(0, diag(Nboxes)) - cbind(diag(Nboxes), 0)

tb <- t(a %*% rbind(0, xx, Nballs+Nboxes) - 1)

Install spymicmac on Ubuntu 22.04 with Anaconda3 installed

 Software micmac can be found here:

https://spymicmac.readthedocs.io/en/v0.1.1/setup.html

When installation was tried using the setup from this page, an error was throwing in relation with qt5. It seems that there was a mistake with Anaconda qt5 installation.

The solution has been to find the directory of installation of qt5 using:

locate /qt5/plugins/

In our case, it was:

/usr/lib/x86_64-linux-gnu/qt5/plugins

Then, rather than doing:

cmake .. -DWITH_QT5=1 -DWERROR=0 -DWITH_CCACHE=OFF

as indicated in the spymicmac documentation, use:

cmake .. -DWITH_QT5=1 -DWERROR=0 -DWITH_CCACHE=OFF -DCMAKE_PREFIX_PATH=/usr/lib/x86_64-linux-gnu/qt5/plugins