How to install and run Scilab manually?

Ok, I just tried installing it, an it worked OK. Here what I did: To install, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:

sudo apt-get install scilab

After the installation was done, I searched for scilab in dash, and clicked on it

After I clicked on it, it opened, and I checked the version, and it was 5.4.1

Hope that helps.

Your terminal command should work, but with the following change:

$ cd scilab-5.4.1
$ cd bin
$ ./scilab

Note the "dot-slash" before "scilab". "Dot" is the current working directory. Your shell was looking for scilab in all of the directories in your PATH environment variable, and not finding it, suggested that you needed to install the package. Do:

echo $PATH

on the command line and you will see which directories are searched.

This is a really common mistake - after a while, including the dot-slash will be second nature. Note you can also include the path structure in the command line launch:

$ cd scilab-5.4.1
$ ./bin/scilab

Hope this helps.

Ubuntu 16.04 LTS:

Once you have downloaded scilab, go to directory in terminal by pressing Crtl + Alt + T, Unzip the package, go to the directory containing scilab. Go to bin and run the command

$ ./scilab  

Scilab 6.0.0

akhilesh_k@akhilesh:~/Programs$ cd sc*
akhilesh_k@akhilesh:~/Programs/scilab-6.0.0$ cd bin
akhilesh_k@akhilesh:~/Programs/scilab-6.0.0/bin$ ./scilab