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1 files changed, 38 insertions, 0 deletions

diff --git a/noao/astutil/pdm/pdmampep.x b/noao/astutil/pdm/pdmampep.x
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+++ b/noao/astutil/pdm/pdmampep.x
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+include <mach.h>
+include <ctype.h>
+include <error.h>
+include "pdm.h"
+
+# PDM_AMPEP -- Calculate the amplitude and epoch for this data.
+
+procedure pdm_ampep (pdmp, period)
+
+pointer	pdmp			# PDM structure pointer
+double	period			# period for which to calculate
+
+int	i, isave
+double	npt, ymin, ymax
+errchk	pdm_phase
+
+begin
+	npt = PDM_NPT(pdmp)
+
+	# Find the maximum and minimum values in the data.
+	# The difference is the amplitude.
+
+	ymax = -MAX_DOUBLE
+	ymin = MAX_DOUBLE
+	do i = 1, npt {
+	    if (PDM_INUSE(pdmp,i) == 0)
+		next
+	    if (PDM_DY(pdmp,i) < ymin)
+		ymin = PDM_DY(pdmp,i)
+	    if (PDM_DY(pdmp,i) > ymax) {
+		ymax = PDM_DY(pdmp,i)
+		isave = i
+	    }
+	}
+
+	PDM_AMPL(pdmp) = ymax - ymin
+	PDM_EPOCH(pdmp) = PDM_X(pdmp, isave)
+end