You will only get an approximation to your original signal.  By the time you have upsampled by 2 and downsampled by 4, you have an overall downsample of 2.  That means you have thrown away half your original data.  No amount of upsampling will perfectly re-construct that lost data.

up sample and down sample
I want to create a text file and open it in a text editor with a single command.

I know touch file.txt creates a file and open file.txt opens the file, but is there a way to do this with a single command?
