Using Fortran Subarrays in f90: Passing Single Columns/Rows into a Subroutine

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SUMMARY

This discussion focuses on passing single columns or rows of arrays in Fortran 90 (f90) subroutines. The user seeks to call a subroutine with a specific array slice, and the consensus confirms that this is feasible if the subroutine's variable is correctly defined. An example provided demonstrates the syntax for passing a column of a 3D array using the CALL statement with an assumed-shape array in the subroutine. Proper array dimensioning is crucial for successful implementation.

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This discussion is beneficial for Fortran developers, particularly those working with array manipulations and subroutine implementations in scientific computing or numerical analysis.

natski
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Dear all,

I am using f90 and trying to pass only one column/row of an array into a subroutine. So I want something like...

call test(x(1,:),...)

If "test" defines the first entry as a vector, will this work?

Natski
 
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It will work, so long as the variable in the subroutine has the proper shape. Also, you're syntax is a little wrong, here's what it would look like:
Code: 
DIMENSION(10,10,10) :: x

CALL test( x(:,1,1) )
END PROGRAM

SUBROUTINE test
DIMENSION(:),INTENT(whatever) :: x
...
There are a few different methods to sizing the array in the subroutine. Often times we'll not specify the size and let the compiler use an "assumed" array sizing.
 

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