Printing Variables with WRITE

[SaharRasoulpour]

I have a question about the output file. I’m trying to print a variable in source code, so I added a write(LU_output) variable_name statement inside the loop in init.f90 (for example, LAYER_DENSITY). I also added global_constant at the top of the init.f90 file. However, after compiling, the variable does not appear in the output file. What could be causing this issue, and how can I modify the code so that the variable actually appears in the output?

[rmcdermo]

Just follow an example in dump.f90. Should look something like this:

write(lu_output,*) some_variable ! do not forget the format specifier *

[SaharRasoulpour]

That is what I did in the for loop of LAYER_DENSITY:

ONE_D%MIN_DIFFUSIVITY(NL) = HUGE_EB
   DO NN=1,ONE_D%N_MATL
      WRITE(LU_OUTPUT,*) 'NN = ', NN
      WRITE(LU_OUTPUT,*) 'NL = ', NL
      WRITE(LU_OUTPUT,*) 'MASS_FRACTION = ', ONE_D%MATL_COMP(NN)%MASS_FRACTION(NL)
      IF (ONE_D%MATL_COMP(NN)%MASS_FRACTION(NL)>TWO_EPSILON_EB) &
         ONE_D%MIN_DIFFUSIVITY(NL) = MIN(ONE_D%MIN_DIFFUSIVITY(NL),MATERIAL(ONE_D%MATL_INDEX(NN))%THERMAL_DIFFUSIVITY)
      LAYER_DENSITY(NL) = LAYER_DENSITY(NL) + ONE_D%MATL_COMP(NN)%MASS_FRACTION(NL) / MATERIAL(ONE_D%MATL_INDEX(NN))%RHO_S

   ENDDO
   WRITE(LU_OUTPUT,*) 'LAYER_DENSITY = ', LAYER_DENSITY(NL)
   CALL FLUSH(LU_OUTPUT)
   LAYER_DENSITY(NL) = 1._EB/LAYER_DENSITY(NL)

yes, I ensured that I compiled the modified code and executed the updated executable.

[mcgratta]

Maybe the .out has not been opened yet at this point in the code. I always use

write(0,*)

to get debug printout either on the screen or piped to the .err file.

[drjfloyd]

I think @mcgratta is correct. In main.f90:

! Initialize global parameters

CALL INITIALIZE_GLOBAL_VARIABLES <---- Write is happening during initialization

...
IF (SETUP_ONLY .OR. CHECK_MESH_ALIGNMENT) THEN
IF (MY_RANK==0) CALL INITIALIZE_DIAGNOSTIC_FILE(DT) <---- Where we open the .out file

I tend to use WRITE(LU_ERR,*) which goes to standard error (screen on windows or the err file). If you write to a unit number that isn't open, you can try checking for fort.unit_number (so here fort,6) to see if a file was opened with the unit number as the name.

[SaharRasoulpour]

I went back to CALL INITIALIZE_GLOBAL_VARIABLES in main.f90 to ensure that LU_output is open. I added WRITE(LU_OUTPUT,*) in this form:

IF (CHECK_MESH_ALIGNMENT) THEN
   IF (MY_RANK==0) CALL INITIALIZE_DIAGNOSTIC_FILE(DT)
   STOP_STATUS = SETUP_ONLY_STOP
   IF (MY_RANK==0) WRITE(LU_ERR,'(A)') ' Checking mesh alignment. This could take a few tens of seconds...'
ELSE
  
   IF (MY_RANK==0) THEN
      CALL INITIALIZE_DIAGNOSTIC_FILE(DT)
      WRITE(LU_OUTPUT,*) 'LU_OUTPUT initialized successfully.'
      CALL FLUSH(LU_OUTPUT)
   ENDIF
ENDIF

CALL STOP_CHECK(1

I compiled and ran the case, and in the output, the following line appeared: "LU_OUTPUT initialized successfully." This indicates that LU_OUTPUT is open. Then, I went to init.f90 and modified the loop related to LAYER_DENSITY to the following form:

LAYER_DENSITY = 0._EB
DO NL=1,ONE_D%N_LAYERS
   DO NN=1,ONE_D%N_MATL
      LAYER_DENSITY(NL) = LAYER_DENSITY(NL) + ONE_D%MATL_COMP(NN)%MASS_FRACTION(NL) / MATERIAL(ONE_D%MATL_INDEX(NN))%RHO_S
   ENDDO
   LAYER_DENSITY(NL) = 1._EB / LAYER_DENSITY(NL)

   WRITE(LU_OUTPUT,*) 'LAYER_DENSITY(', NL, ') = ', LAYER_DENSITY(NL)
   CALL FLUSH(LU_OUTPUT)  ! Ensures output is written immediately
ENDDO

I expected to see LAYER_DENSITY(1) = ..., LAYER_DENSITY(2) = ..., etc. However, unfortunately, after "LU_OUTPUT initialized successfully.", nothing appeared. I changed it to WRITE(0,) and WRITE(LU_ERR,), but still, nothing happened. I want to know if what I did is correct. To resolve this issue, what should I do?

[mcgratta]

If you have a write statement in a loop, and you get no output, then put a write statement in front of the loop and write out, for example, ONE_D%N_LAYERS. You may not be entering the loop