Writing a waveform and sampled version of that into a file without using ocnPrint

There's no need to open in append mode unless you want to append to the previous contents of the file (i.e. not overwrite it at the time of opening). Each succesive ocnPrint with the same port will append to the output stream until the file is closed.

You can't use fprintf with a waveform object; you'd have to iterate over the points in the waveform object - for example:

/* abDumpWaveform.il

Author     A.D.Beckett
Group      Custom IC, Cadence Design Systems Ltd.
Machine    SUN
Date       Oct 23, 1997 
Modified   Jan 31, 2005 
By         A.D.Beckett

Functions for dumping a waveform to a file

Examples:

abDumpWaveform(VT("/c") "data_c.out")
abDumpWaveform(VT("/c") "data_c.out" "%e %e\n") ;; exponential format

abDumpWaveformSplit() is equivalent to abDumpWaveform, but splits
into files a little less than 2Gbytes (the split limit is an optional
argument).

;; sampled output.
;; note that linRg and logRg generate a range of values,
;; with args from, to, step.
abDumpSampledWaveform(VT("/c") linRg(0.01 0.05 0.005) "data_c.out")

;; multi-variable output
;; all waveforms must share same x-axis, as it doesn't do any interpolation (for
;; speed reasons). Interpolation could be done by collecting all the x-values, and
;; then using the value function.
abDumpWaveforms("data.out" VT("/c") VT("/z") VT("/a"))
abDumpWaveforms("data.out" VT("/c") VT("/z") VT("/a") ?format "%-10g" ?separator ",")

;; can also write out multiple files if presented with a family
abDumpFamily(VT("/c") "data.out")

***************************************************

SCCS Info: @(#) abDumpWaveform.il 11/20/08.15:26:13 1.6

*/

/*****************************************************************
*                                                                *
*  (abDumpWaveform wave fileName @optional (format "%g %g\n"))   *
*                                                                *
* Take a waveform object, write it out to the fileName specified *
*          with the format given. No sampling is done.           *
*                                                                *
*****************************************************************/

(procedure (abDumpWaveform wave fileName @optional (format "%g %g\n"))
  (let (port (xVec (drGetWaveformXVec wave))
             (yVec (drGetWaveformYVec wave)))
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (for pos 0 (sub1 (drVectorLength xVec))
            (fprintf port format
                     (drGetElem xVec pos)
                     (drGetElem yVec pos))
            )
       (close port)
       ))

/*****************************************************************
*                                                                *
*         (abDumpWaveformSplit wave fileName @optional           *
*            (format "%g %g\n") (split 2**31-512) )              *
*                                                                *
* Take a waveform object, write it out to the fileName specified *
*     with the format given. No sampling is done. Splits into    *
*      multiple files when the number of bytes exceeds split     *
*                                                                *
*****************************************************************/

(procedure (abDumpWaveformSplit wave fileName @optional (format "%g %g\n") (split 2**31-512))
  (let (port (xVec (drGetWaveformXVec wave))
             (yVec (drGetWaveformYVec wave))
             str (len 0) (suffix 0))
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (for pos 0 (sub1 (drVectorLength xVec))
            (sprintf str format
                     (drGetElem xVec pos)
                     (drGetElem yVec pos))
            (setq len (plus (strlen str) len))
            (when (greaterp len split)
                  (close port)
                  (postincrement suffix)
                  (setq len (strlen str))
                  (unless (setq port (outfile (sprintf nil "%s_%d" fileName suffix)))
                          (error "Could not write to file %s_%d\n" fileName suffix))
                  )
            (fprintf port "%s" str)
            )
       (close port)
       ))

/********************************************************************
*                                                                   *
* (abDumpFamily family fileNamePrefix @optional (format "%g %g\n")) *
*                                                                   *
* Write out a sequence of files for a family. Could potentially do  *
*  this automatically inside abDumpWaveform, but it's hard without  *
*                     using private functions.                      *
*                                                                   *
********************************************************************/

(procedure (abDumpFamily family fileNamePrefix @optional (format "%g %g\n"))
  (let ((xVec (drGetWaveformXVec family))
        (yVec (drGetWaveformYVec family))
        index
        )
       (if (drIsWaveform family)
           ; then
           (abDumpWaveform family fileNamePrefix format)
           ;else
           (for pos 0 (sub1 (drVectorLength xVec))
                (setq index (drGetElem xVec pos))
                (unless (stringp index)
                        (sprintf index "%L" index))
                (rexCompile "[^a-zA-Z0-9.]")
                (setq index (rexReplace index "_" 0))
                (abDumpWaveform
                 (drGetElem yVec pos)
                 (sprintf nil "%s_%s" fileNamePrefix index)
                 format
                 )
                )
           ) ; if
       ))

/*********************************************************************************
*                                                                                *
*   (abDumpWaveforms fileName @key (format "%g") (separator " ") @rest waves)    *
*                                                                                *
*    Write out a group of waveforms with a common x-axis to a file. It checks    *
* to see if the x-axis is the same, because otherwise some kind of interpolation *
*    would be necessary. An optional format string can be specified, so that     *
*   the precision can be controlled. Also, an optional separator may be given.   *
*                                                                                *
*********************************************************************************/

(procedure (abDumpWaveforms fileName @key (format "%g") (separator " ") @rest waves)
  (let (port xVec)
       (setq xVec (drGetWaveformXVec (car waves)))
       ;-----------------------------------------------------------------
       ; check to see if all waveforms have same X-axis
       ;-----------------------------------------------------------------
       (when (exists wave waves (neq xVec (drGetWaveformXVec wave)))
             (error "All waveforms must have same x-axis")
             )
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (for pos 0 (sub1 (drVectorLength xVec))
            (fprintf port format
                     (drGetElem xVec pos))
            (foreach wave waves
                     (fprintf port "%s" separator)
                     (fprintf port format (drGetElem (drGetWaveformYVec wave) pos))
                     )
            (fprintf port "\n")
            )
       (close port)
       ))

/**********************************************************************************
*                                                                                 *
* (abDumpSampledWaveform wave samplePoints fileName @optional (format "%g %g\n")) *
*                                                                                 *
*      Dump the waveform at the sampled points passed in. wave is a waveform      *
*            object, samplePoints is a list of x points to sample at,             *
* fileName is the file to write to, and format is an optional formatting string.  *
*                                                                                 *
**********************************************************************************/

(procedure (abDumpSampledWaveform wave samplePoints fileName @optional (format "%g %g\n"))
  (let (port) 
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (foreach point samplePoints
                (fprintf port format
                         point
                         (value wave point))
                )
       (close port)
       ))

There's no need to open in append mode unless you want to append to the previous contents of the file (i.e. not overwrite it at the time of opening). Each succesive ocnPrint with the same port will append to the output stream until the file is closed.

You can't use fprintf with a waveform object; you'd have to iterate over the points in the waveform object - for example:

/* abDumpWaveform.il

Author     A.D.Beckett
Group      Custom IC, Cadence Design Systems Ltd.
Machine    SUN
Date       Oct 23, 1997 
Modified   Jan 31, 2005 
By         A.D.Beckett

Functions for dumping a waveform to a file

Examples:

abDumpWaveform(VT("/c") "data_c.out")
abDumpWaveform(VT("/c") "data_c.out" "%e %e\n") ;; exponential format

abDumpWaveformSplit() is equivalent to abDumpWaveform, but splits
into files a little less than 2Gbytes (the split limit is an optional
argument).

;; sampled output.
;; note that linRg and logRg generate a range of values,
;; with args from, to, step.
abDumpSampledWaveform(VT("/c") linRg(0.01 0.05 0.005) "data_c.out")

;; multi-variable output
;; all waveforms must share same x-axis, as it doesn't do any interpolation (for
;; speed reasons). Interpolation could be done by collecting all the x-values, and
;; then using the value function.
abDumpWaveforms("data.out" VT("/c") VT("/z") VT("/a"))
abDumpWaveforms("data.out" VT("/c") VT("/z") VT("/a") ?format "%-10g" ?separator ",")

;; can also write out multiple files if presented with a family
abDumpFamily(VT("/c") "data.out")

***************************************************

SCCS Info: @(#) abDumpWaveform.il 11/20/08.15:26:13 1.6

*/

/*****************************************************************
*                                                                *
*  (abDumpWaveform wave fileName @optional (format "%g %g\n"))   *
*                                                                *
* Take a waveform object, write it out to the fileName specified *
*          with the format given. No sampling is done.           *
*                                                                *
*****************************************************************/

(procedure (abDumpWaveform wave fileName @optional (format "%g %g\n"))
  (let (port (xVec (drGetWaveformXVec wave))
             (yVec (drGetWaveformYVec wave)))
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (for pos 0 (sub1 (drVectorLength xVec))
            (fprintf port format
                     (drGetElem xVec pos)
                     (drGetElem yVec pos))
            )
       (close port)
       ))

/*****************************************************************
*                                                                *
*         (abDumpWaveformSplit wave fileName @optional           *
*            (format "%g %g\n") (split 2**31-512) )              *
*                                                                *
* Take a waveform object, write it out to the fileName specified *
*     with the format given. No sampling is done. Splits into    *
*      multiple files when the number of bytes exceeds split     *
*                                                                *
*****************************************************************/

(procedure (abDumpWaveformSplit wave fileName @optional (format "%g %g\n") (split 2**31-512))
  (let (port (xVec (drGetWaveformXVec wave))
             (yVec (drGetWaveformYVec wave))
             str (len 0) (suffix 0))
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (for pos 0 (sub1 (drVectorLength xVec))
            (sprintf str format
                     (drGetElem xVec pos)
                     (drGetElem yVec pos))
            (setq len (plus (strlen str) len))
            (when (greaterp len split)
                  (close port)
                  (postincrement suffix)
                  (setq len (strlen str))
                  (unless (setq port (outfile (sprintf nil "%s_%d" fileName suffix)))
                          (error "Could not write to file %s_%d\n" fileName suffix))
                  )
            (fprintf port "%s" str)
            )
       (close port)
       ))

/********************************************************************
*                                                                   *
* (abDumpFamily family fileNamePrefix @optional (format "%g %g\n")) *
*                                                                   *
* Write out a sequence of files for a family. Could potentially do  *
*  this automatically inside abDumpWaveform, but it's hard without  *
*                     using private functions.                      *
*                                                                   *
********************************************************************/

(procedure (abDumpFamily family fileNamePrefix @optional (format "%g %g\n"))
  (let ((xVec (drGetWaveformXVec family))
        (yVec (drGetWaveformYVec family))
        index
        )
       (if (drIsWaveform family)
           ; then
           (abDumpWaveform family fileNamePrefix format)
           ;else
           (for pos 0 (sub1 (drVectorLength xVec))
                (setq index (drGetElem xVec pos))
                (unless (stringp index)
                        (sprintf index "%L" index))
                (rexCompile "[^a-zA-Z0-9.]")
                (setq index (rexReplace index "_" 0))
                (abDumpWaveform
                 (drGetElem yVec pos)
                 (sprintf nil "%s_%s" fileNamePrefix index)
                 format
                 )
                )
           ) ; if
       ))

/*********************************************************************************
*                                                                                *
*   (abDumpWaveforms fileName @key (format "%g") (separator " ") @rest waves)    *
*                                                                                *
*    Write out a group of waveforms with a common x-axis to a file. It checks    *
* to see if the x-axis is the same, because otherwise some kind of interpolation *
*    would be necessary. An optional format string can be specified, so that     *
*   the precision can be controlled. Also, an optional separator may be given.   *
*                                                                                *
*********************************************************************************/

(procedure (abDumpWaveforms fileName @key (format "%g") (separator " ") @rest waves)
  (let (port xVec)
       (setq xVec (drGetWaveformXVec (car waves)))
       ;-----------------------------------------------------------------
       ; check to see if all waveforms have same X-axis
       ;-----------------------------------------------------------------
       (when (exists wave waves (neq xVec (drGetWaveformXVec wave)))
             (error "All waveforms must have same x-axis")
             )
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (for pos 0 (sub1 (drVectorLength xVec))
            (fprintf port format
                     (drGetElem xVec pos))
            (foreach wave waves
                     (fprintf port "%s" separator)
                     (fprintf port format (drGetElem (drGetWaveformYVec wave) pos))
                     )
            (fprintf port "\n")
            )
       (close port)
       ))

/**********************************************************************************
*                                                                                 *
* (abDumpSampledWaveform wave samplePoints fileName @optional (format "%g %g\n")) *
*                                                                                 *
*      Dump the waveform at the sampled points passed in. wave is a waveform      *
*            object, samplePoints is a list of x points to sample at,             *
* fileName is the file to write to, and format is an optional formatting string.  *
*                                                                                 *
**********************************************************************************/

(procedure (abDumpSampledWaveform wave samplePoints fileName @optional (format "%g %g\n"))
  (let (port) 
       (unless (setq port (outfile fileName))
               (error "Could not write to file %s\n" fileName))
       (foreach point samplePoints
                (fprintf port format
                         point
                         (value wave point))
                )
       (close port)
       ))