Experimental Physics and
Industrial Control System

"F. Gougnaud" <[email protected]> · Mon, 13 Feb 95 14:39:42 GMT

	Hi,

	I have corrected a bug in the recCompress.c file in EPICS release 3.11.

The AVERAGE algorithm doesn't work when the N field is greater than 1 (!)
because the routine array_average() doesn't update the INX record's field.

The routine must be modified like this:

	...
	/* do we need to calculate the result */
	inx++;
	if (pcompress->n<=0) pcompress->n=1;
	n = pcompress->n;
	pcompress->inx = inx;    <---- add this line
	if (inx<n) return(1);
	if (n>1) {
		pcompress->inx = 0;    <---- and this line
		psum = (double *)pcompress->sptr;
		multiplier = 1.0/((double)n);
		for (i = 0; i < nuse; i++, psum++)
	    		*psum = *psum * multiplier;
	}
	put_value(pcompress,pcompress->sptr,nuse);
	return(0);

A suggestion for the compress record type:

in 3.11 it's not possible to modify the N field of a compress record from
an application. For that, the N field definition in the compressRecord.ascii
file need to be changed like this:

(before)    "N to 1 Compression"     N    SPC_NOMOD  DBF_ULONG   ...
(after)     "N to 1 Compression"     N    SPC_RESET  DBF_ULONG   ...

	Yves Lussignol.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System