Functions

import ROOT

import fortranmagic
%load_ext fortranmagic
import os
import sys

import numpy as np

if sys.platform.startswith("win"):
        # Depends of system, python builds, and compilers compatibility.
        # See below.
    f_config = "--fcompiler=gnu95 --compiler=mingw32"
else:
        # For Unix, compilers are usually more compatible.
    f_config = ""

    # Disable only deprecated NumPy API warning without disable any APIs.
f_config += " --extra '-DNPY_NO_DEPRECATED_API=0'"

%fortran_config {f_config}

New default arguments for %fortran:
	 --extra '-DNPY_NO_DEPRECATED_API=0'

c++

%%cpp -d
double square(double d){
    return d*d;
}
int fib(int x) {
   if((x==1)||(x==0)) {
      return(x);
   }else {
      return(fib(x-1)+fib(x-2));
   }
}

%%cpp
cout <<square(2)<<" "<<fib(30)<<endl;

4 832040

c

%%cpp

printf("%lf",square(2.));

4.000000

javascript

%%js //the next line is only necessary in jupyter notebooks
element.setAttribute('style', 'white-space: pre;');console.log=function(text){element.textContent+=text+"\n"}

function square(d){
    return d*d;
}
console.log(square(2))

Python

def square(d):
    return d*d;

print(square(2))

4

Fortran

%%fortran 

! program and subroutine exchanged due to jupyternotebook

! program main
subroutine main()
    implicit none
    integer :: fib
    real*8::square

    print *,square(7.8d0)
    print *,fib(10)
    call test(5d0)
    ! read *  ! only works in compiled program
! end program
end subroutine main

real*8 function square(d)
    implicit none
    real*8,intent(in)::d  ! intent can be "in", "out" or "inout"
    square=d*d
end function

subroutine test(d)
    implicit none
    real*8,intent(in)::d
    print *,d
end subroutine

pure recursive integer function fib(n) result(f) ! pure make no global variables accessible
    implicit none
    integer, intent(in) :: n
    if (n <= 1) then
        f = n
    else
        f = fib(n-1) + fib(n-1)
    end if
end function fib

main()

   60.839999999999996     
         512
   5.0000000000000000