r - Having issues installing gam package in RStudio ver. 3.6.2

Question

I have been trying a lot of different ways to install this package such as:

• using dependencies argument
• installing from binary zip file

But I keep getting the following error:

* installing *source* package ‘gam’ ...
** package ‘gam’ successfully unpacked and MD5 sums checked
** using staged installation
** libs
gfortran  -fPIC  -Wall -g -O2  -c backfit.f -o backfit.o
make: gfortran: No such file or directory
make: *** [backfit.o] Error 1
ERROR: compilation failed for package ‘gam’
* removing ‘/Users/username/Library/R/3.6/library/gam’
* restoring previous ‘/Users/username/Library/R/3.6/library/gam’
Warning in install.packages :
  installation of package ‘gam’ had non-zero exit status

The downloaded source packages are in
    ‘/private/var/folders/78/90s7m_qn425994767scnt9nh0000gn/T/RtmpvWmhBQ/downloaded_packages’

标签： rpackagegam