R Loading xlsx problem

require(xlsx)
Loading required package: xlsx
Loading required package: rJava
Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: fun(libname, pkgname)
  error: No CurrentVersion entry in Software/JavaSoft registry! Try re-installing Java and make sure R and Java have matching architectures.
Failed with error:  ‘package ‘rJava’ could not be loaded’


Problem answered by http://stackoverflow.com/questions/17376939/problems-when-trying-to-load-a-package-in-r-due-to-rjava

The reason is probably linked to the fact you are using a 64-bit OS and R version but do not have Java installed with the same architecture. What you have to do is to download Java 64-bit from this page: https://www.java.com/en/download/manual.jsp After that just try to reload the xlxs package. You shouldn't need to re-start R.

how to change the alt-tab application switcher in ubuntu unity

Original post is from here : http://ubuntuforums.org/showthread.php?t=2211863



sudo apt-get install compizconfig-settings-manager
sudo apt-get install compiz-plugins

Open compizconfig-settings-manager with alt-F2, type ccsm.

Scroll down to "Ubuntu Unity Plugin". Choose the tab "Switcher". Disable the alt-tab and shift-alt-tab key bindings. ("Key to start the switcher" and "Key to switch to the previous window in the Switcher".
Click the "Back" button.

Scroll down to the "Window management" section. Here you can select another switcher.
I enable the "Static Application Switcher", resolve any potential conflicts by setting the setting for "Static Application Switcher".
Now you can tweak the switcher by clicking on it. I have changed alt-tab and shift-alt-tab to "Next window (All windows)" and "Prev window (All windows)".

Experiment to find the settings that work best for you. It you want to go back to the poriginal settings, simply disable the Static Application Switcher and enable the key bindings in "Ubuntu Unity Plugin" again.