How Can I Correctly Use the 'dacos' Function in a Fortran Header File?

[paulga]

I came across a problem on the project:
my project is comprised of tens of fortran files. There is a param.h header file collecting all the parameters that are used by the program and subroutines. but after I add this line:
parameter(pi = dacos(-1.0d0))
into the param.h
the command "make " always reports errors like:

param.h: In subroutine `stressinit':
param.h:135:
parameter(pi = dacos(-1.0d0))
^
Invalid declaration of or reference to symbol `dacos' at (^) [initially seen at (^)]

How to employ the function "dacos" in a header file?
Thanks a lot.

 

[NateD]

You need to add a declaration for the dacos() function in the param.h header file. This can be done using the following syntax: double precision function dacos(x) double precision, intent(in) :: x dacos = ... end function dacos

 

[oswaler]

Hello,

It seems like you are having trouble with using the function "dacos" in your param.h header file. The error message you received indicates that there is an invalid declaration or reference to the symbol "dacos" in your code. This could be due to a few reasons:

1. The function "dacos" is not defined in your code or in any of the Fortran files that you are using. Make sure that you have included the necessary libraries or modules that contain the definition for this function.

2. The function "dacos" is not spelled correctly. Fortran is case sensitive, so make sure that you are using the correct capitalization for the function name.

3. The function "dacos" is not compatible with the data type you are using. Make sure that the input for the function is of the correct data type (in this case, a double precision number).

If none of these suggestions help, it would be helpful to see the specific code in your param.h header file and any associated files in order to provide a more specific solution. I would also recommend consulting with other Fortran experts or checking online resources for further assistance with this issue.

Best of luck with your project.