[Fortran 90/95] Error: function has no IMPLICIT type

Click For Summary
SUMMARY

The forum discussion addresses a compilation error in Fortran 95 related to the function 'BMatScal', which is reported as having no IMPLICIT type. The issue arises from the use of the 'PRIVATE' keyword without explicitly declaring 'BMatScal' as 'PUBLIC'. The solution involves either removing the 'PRIVATE' declaration or explicitly declaring 'BMatScal' as 'PUBLIC' to ensure it is accessible in the program. This highlights the importance of understanding module visibility in Fortran programming.

PREREQUISITES
  • Understanding Fortran 90/95 syntax and structure
  • Familiarity with module and function definitions in Fortran
  • Knowledge of IMPLICIT typing and visibility rules in Fortran
  • Experience with matrix operations in Fortran, specifically using MATMUL
NEXT STEPS
  • Research Fortran 90/95 module visibility and access specifiers
  • Learn about the implications of IMPLICIT NONE in Fortran
  • Explore best practices for organizing Fortran modules and functions
  • Investigate advanced matrix operations in Fortran, including the use of intrinsic functions
USEFUL FOR

This discussion is beneficial for Fortran developers, particularly those working on numerical methods and matrix computations, as well as educators teaching Fortran programming concepts.

ted_kingdom
Messages
5
Reaction score
0
Hi!
I get an error when trying to compile my program:
Code:
test8.f95:26.8:

 BMat = BMatScal(InverseJacobian, ShapeFuncDeriv)
        1
Error: Function 'bmatscal' at (1) has no IMPLICIT type

I don't know why it complains because I specified type of the function in its definition (please see code below):
Code:
MODULE q12
	INTEGER, PARAMETER,PUBLIC::NDIM=2,NNODES=4, NDIR = 2, NSHR = 1
END MODULE q12

MODULE BMatricesScalar
	IMPLICIT NONE
	PRIVATE
	CONTAINS
! BMatScal function provides B-matrix for scalar-valued variable (e.g. temperature)
		FUNCTION BMatScal(JacobiInv, ShapeFuncDeriv)
			REAL, INTENT(IN) :: JacobiInv(:,:), ShapeFuncDeriv(:,:)
			REAL :: BMatScal(SIZE(JacobiInv,1),SIZE(ShapeFuncDeriv,2))
			
			BMatScal = MATMUL(JacobiInv, ShapeFuncDeriv)
		END FUNCTION BMatScal
END MODULE BMatricesScalar

PROGRAM q2
	USE q12
	USE BMatricesScalar
	IMPLICIT NONE
	REAL:: InverseJacobian(2,2) = RESHAPE((/1,1,1,1/),(/2,2/)),&
			 ShapeFuncDeriv(2,4) = RESHAPE((/0.0,-0.5,0.0,0.0,0.5,0.0,-0.5,0.5/),(/2,4/)),&
			 BMat(NDIR,NNODES)
			 
	BMat = BMatScal(InverseJacobian, ShapeFuncDeriv)
	PRINT*, BMat(1,:)
	PRINT*, BMat(2,:)
END PROGRAM q2

What am I missing? Thanks in advance.
 
Last edited:
Technology news on Phys.org
Have you added 'use BMatriceScalar' in your program?
 
Ah I see you have. My mistake. Try removing 'private'
 
  • Like
Likes   Reactions: 1 person
a_potato, you are right. I changed default setting by omitting :: after PRIVATE. Thank you for noticing it!
 
This is a little late, but it's worth mentioning that you can have the module entries to be private as default and then explicitly list the thing you want to expose publically. So you could have,

PRIVATE ! module members are private by default
PUBLIC :: BMatScal ! I want BMatScal to be publicThis way you can define internal constants and functions without worrying that they will collide with other modules members when you "use" them.
and then the use statement would recognize it.
 
  • Like
Likes   Reactions: 1 person
Allday, yes, you're right. This would be an option as well. Thank you.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K