Difference between revisions of "Guide for good coding"
Romain.vande (talk | contribs) (→How to create a new module/subroutine) |
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c author: Someone | c author: Someone | ||
Revision as of 11:06, 5 January 2023
Contents
How to create a new module/subroutine
Subroutines should be integrated inside a module. A good writing habit is to add the line "IMPLICIT NONE", in the beginning of the module and subroutine.
First you can define all the variable that belongs to the module and could be used at another place. A good thing is also to create a subroutine that allocate and initialise module variables. If the variable is only modified inside the module it should be tag as protected. If the variable belongs only to the module it can be specified to be private.
You can now start the definition of the subroutine. Start by variable and function from other module if necessary. Comment the purpose of the subroutine directly. Declare the variables, first the one pass in arguments. Use the intent to specify the status of the variable inside the subroutine. Continue with the local and saved variables. Then you can define local variables. Remember to comment all of them, you can specify the dimension if the variable is an allocatable variable.
1 MODULE aquarium_mod
2
3 IMPLICIT NONE
4
5 INTEGER :: water ! Define what is the variable, the dimension, units etc..
6 REAL,SAVE,ALLOCATABLE,DIMENSION(:) :: kre1 ! Another comment (°)
7
8 CONTAINS
9
10 SUBROUTINE ini_aquarium(ngrid)
11 c=======================================================================
12 c subject:
13 c --------
14 c Initialise module s variable
15 c
16 c author: Someone
17 c=======================================================================
18 IMPLICIT NONE
19 INTEGER, INTENT(IN) :: ngrid
20
21 allocate(kre1(ngrid+1))
22
23 END SUBROUTINE ini_aquarium
24
25 SUBROUTINE end_aquarium
26 c=======================================================================
27 c subject:
28 c --------
29 c Deallocate module s variable
30 c
31 c author: Someone
32 c=======================================================================
33
34 IMPLICIT NONE
35
36 IF (allocated(kre1)) deallocate(kre1)
37
38 END SUBROUTINE end_aquarium
39
40 SUBROUTINE aquarium(kre, grass, other_things
41 & really_anything)
42
43 use another_module_mod, only: fct, variable
44
45 c=======================================================================
46 c subject:
47 c --------
48 c What is the subroutine doing
49 c
50 c author: Someone smart
51 c ------
52 c update: Someone smarter, march 2012:
53 c - I change something here
54 c
55 c=======================================================================
56
57 IMPLICIT NONE
58
59 c-----------------------------------------------------------------------
60 c
61 c Declarations :
62 c --------------
63 c
64 c Input/Output
65 c ------------
66
67 REAL, INTENT(IN) :: something(ngrid,nlayer) ! 2D tabular used as an input only (W/m^2)
68 REAL, INTENT(OUT) :: kre(ngrid) ! 1D tabular output by the subroutine
69 REAL, INTENT(INOUT) :: grass(ngrid,nlayer) ! Variable that is modified by the subroutine
70 ! it is an input and output
71 LOGICAL,INTENT(IN) :: really_anything ! Boolean variable
72
73 c Local saved variables :
74 c -----------------
75 INTEGER, PARAMETER :: nb_kre = 6 ! Number of kre
76 INTEGER, SAVE :: rock ! Another variable
77 LOGICAL,SAVE :: firstcall=.true. ! Another variable
78
79 c Local variables :
80 c -----------------
81 REAL tabular(ngrid) ! Local var
82 INTEGER i ! Loop var
83
84 c Beginning of the code :
85 c -----------------
86
87 IF (firstcall) THEN
88 ! identify where are the kre
89 DO i=1,nb_kre
90 kre(i)=i
91 write(*,*) "the Kre ", i, "is behind the rock"
92 ENDDO !end of the loop nb_kre
93 ENDIF !end firstcall
94
95 END SUBROUTINE aeropacity
96
97 END MODULE aeropacity_mod
