loadPPIN not working and other packages improvement

[MathurinD]

Hi,

You should use system.file('extdata', 'biogridHomoSapiens3.5.166.graphml', package='scPPIN') and not "./inst/extdata/biogridHomoSapiens3.5.166.graphml" to find the file in loadPPIN.
The relative path specification only works if you run the function from the main folder.

Another think you could consider doing is having the R/ folder as a submodule so that it can be installed directly using 'devtools::install_github()'.

[MathurinD]

Same problem with system("./dapcstp DAPCSTP_temp.stp --type pcstp -o DAPCSTP_temp.sol")