ufbstp.f File Reference

Read/write one or more data values from/to a data subset. More...

Go to the source code of this file.

Functions/Subroutines
recursive subroutine	ufbstp (LUNIN, USR, I1, I2, IRET, STR)
	This subroutine reads or writes one or more data values from or to the BUFR data subset that is currently open within the BUFRLIB internal arrays. More...

Detailed Description

Read/write one or more data values from/to a data subset.

Author

J. Woollen

Date

1994-01-06

Definition in file ufbstp.f.

Function/Subroutine Documentation

ufbstp()

recursive subroutine ufbstp	(		LUNIN,
		real*8, dimension(i1,i2)	USR,
			I1,
			I2,
			IRET,
		character*(*)	STR
	)

This subroutine reads or writes one or more data values from or to the BUFR data subset that is currently open within the BUFRLIB internal arrays.

The direction of the data transfer is determined by the context of ABS(LUNIN):

• If ABS(LUNIN) points to a file that was previously opened for input using subroutine openbf(), then data values are read from the current data subset.
• If ABS(LUNIN) points to a file that was previously opened for output using subroutine openbf(), then data values are written to the current data subset.

This subroutine is specifically designed for use with Table B mnemonics which are part of a fixed (i.e. non-delayed) replication sequence, or for mnemonics which are replicated by being directly listed more than once within an overall subset definition. It is very similar to subroutine ufbrep(), but it differs in how it processes the input mnemonic string STR. For more details, see the discussion and example use case in DX BUFR Tables. See also subroutines ufbint() and ufbseq(), which can also be used to read/write one or more data values from/to a data subset but are also designed for different use cases as noted in DX BUFR Tables.

It is the user's responsibility to ensure that USR is dimensioned sufficiently large enough to accommodate the number of data values that are to be read from or written to the data subset. Note also that USR is an array of real*8 values; therefore, any data that are to be written out as character (i.e. CCITT IA5) values in BUFR must be converted from character into real*8 format within the application program before calling this subroutine. Conversely, when this subroutine is being used to read character values from a data subset, the value that is returned will be in real*8 format and must be converted back into character format by the application program before it can be used as such. Alternatively, there are different subroutines such as readlc() and writlc() which can be used to read/write character data directly from/to a data subset without the need to convert from/to real*8 format as an intermediate step.

Numeric (i.e. non-character) data values within USR are always in the exact units specified for the corresponding mnemonic within the relevant DX or master BUFR table, without any scale or reference values applied. Specifically, this means that, when writing data values into an output subset, the user only needs to store each respective value into USR using the units specified within the table, and the BUFRLIB software will take care of any necessary scaling or referencing of the value before it is actually encoded into BUFR. Conversely, when reading data values from an input subset, the values returned in USR are already de-scaled and de-referenced and, thus, are already in the exact units that were defined for the corresponding mnemonics within the table.

"Missing" values in USR are always denoted by a unique placeholder value. This placeholder value is initially set to a default value of 10E10_8, but it can be reset to any substitute value of the user's choice via a separate call to subroutine setbmiss(). In any case, and whenever this subroutine is used to read data values from an input subset, any returned value in USR can be easily checked for equivalence to the current placeholder value via a call to function ibfms(), and a positive result means that the value for the corresponding mnemonic was encoded as "missing" in BUFR (i.e. all bits set to 1) within the original data subset. Conversely, whenever this subroutine is used to write data values to an output subset, the current placeholder value can be obtained via a separate call to function getbmiss(), and the resulting value can then be stored into the USR array whereever the user desires a BUFR "missing" value (i.e. all bits set to 1) to be encoded for the corresponding mnemonic within the output subset.

Remarks

• If LUNIN < 0, and if ABS(LUNIN) points to a file that is open for output (writing BUFR), then the subroutine will treat the file pointed to by ABS(LUNIN) as though it was open for input (reading BUFR). This is a special capability for use by some applications that need to read certain values back out from a BUFR file during the same time that it is in the process of being written to.

Parameters

[in]	LUNIN	– integer: Absolute value is Fortran logical unit number for BUFR file
[in,out]	USR	– real*8(*,*): Data values If ABS(LUNIN) was opened for input, then USR is output from this subroutine and contains data values that were read from the current data subset. If ABS(LUNIN) was opened for output, then USR is input to this subroutine and contains data values that are to be written to the current data subset.
[in]	I1	– integer: First dimension of USR as allocated within the calling program
[in]	I2	– integer: If ABS(LUNIN) was opened for input, then I2 must be set equal to the second dimension of USR as allocated within the calling program If ABS(LUNIN) was opened for output, then I2 must be set equal to the number of replications of STR that are to be written to the data subset
[out]	IRET	– integer: Number of replications of STR that were read/written from/to the data subset
[in]	STR	– character*(*): String of blank-separated Table B mnemonics in one-to-one correspondence with the number of data values that will be read/written from/to the data subset within the first dimension of USR (see DX BUFR Tables for further information about Table B mnemonics)

Author

J. Woollen

Date

1994-01-06

Definition at line 115 of file ufbstp.f.

References modv_bmiss::bmiss, bort(), bort2(), errwrt(), modv_im8b::im8b, moda_msgcwd::inode, moda_usrint::inv, status(), string(), ufbsp(), x48(), and x84().