Full width at five percent maximum height calculation added.

CrawdadSharp/CrawPeakAnnotator.cs

@@ -28,6 +28,7 @@ void peak_annotate(SlimCrawPeak peak)
             //calls set_peak_areas onpeak member variables
             set_peak_bg_subtracted_area(peak);
             calc_fwhm(peak);
+            calc_fwfpcnt(peak);
         }
 
         int calc_len(int start_rt_idx, int stop_rt_idx) => stop_rt_idx - start_rt_idx + 1;
@@ -364,6 +365,52 @@ public void calc_fwhm(SlimCrawPeak peak)
             peak.fwhm = rh_hm - lh_hm;
         }
 
+        public void calc_fwfpcnt(SlimCrawPeak peak)
+        {
+            float[] chrom = active_chrom;
+            float lh_height = chrom[peak.start_rt_idx];
+            float rh_height = chrom[peak.stop_rt_idx];
+            float height = peak.raw_height - Math.Min(lh_height, rh_height);
+            float fpct_max = (float)(peak.raw_height - (height / 100 * 95));
+            int lh_pt = -1, rh_pt = -1;
+            float lh_hm, rh_hm;
+            for (int i = peak.start_rt_idx; i < peak.peak_rt_idx; i++)
+            {
+                if (chrom[i] <= fpct_max && chrom[i + 1] >= fpct_max)
+                {
+                    lh_pt = i;
+                    break;
+                }
+            }
+            for (int i = peak.peak_rt_idx; i < Math.Min(peak.stop_rt_idx, chrom.Length - 2); i++)
+            {
+                if (chrom[i] >= fpct_max && chrom[i + 1] <= fpct_max)
+                {
+                    rh_pt = i;
+                    break;
+                }
+            }
+
+            if (lh_pt == -1)
+            {
+                lh_hm = peak.start_rt_idx;
+            }
+            else
+            {
+                float frac_delta = (fpct_max - chrom[lh_pt]) / (chrom[lh_pt + 1] - chrom[lh_pt]);
+                lh_hm = lh_pt + frac_delta;
+            }
+            if (rh_pt == -1)
+            {
+                rh_hm = peak.stop_rt_idx;
+            }
+            else
+            {
+                float frac_delta = (chrom[rh_pt] - fpct_max) / (chrom[rh_pt] - chrom[rh_pt + 1]);
+                rh_hm = rh_pt + frac_delta;
+            }
+            peak.fwfpct = rh_hm - lh_hm;
+        }
         public void refind_peak_peak(SlimCrawPeak peak)
         {
             peak.peak_rt_idx = get_peakloc_in_range(peak.start_rt_idx, peak.stop_rt_idx);

CrawdadSharp/CrawdadPeak.cs

@@ -18,6 +18,7 @@ public CrawdadPeak(SlimCrawPeak crawPeak)
             BackgroundArea = Math.Max(0.0f, crawPeak.bg_area);
             Fwhm = crawPeak.fwhm;
             FwhmDegenerate = !crawPeak.fwhm_calculated_ok;
+            Fwfpct = crawPeak.fwfpct;
         }
 
         public int TimeIndex { get; }
@@ -29,6 +30,7 @@ public CrawdadPeak(SlimCrawPeak crawPeak)
         public float BackgroundArea { get; }
         public float Height { get; }
         public float Fwhm { get; }
+        public float Fwfpct { get; }
         public bool FwhmDegenerate { get; }
 
         public bool IsIdentified(IEnumerable<int> idIndices)

CrawdadSharp/CrawdadPeakFinder.cs

@@ -130,7 +130,33 @@ void SetChromatogram(float[] intensities, int maxIntensityIndex, double baseline
             }
             FullWidthHalfMax = fwhm;
 
-            _widthDataWings = (int)(FullWidthHalfMax * 2);
+            int fwfpcnt = 0;
+            if (maxIntensityIndex != -1)
+            {
+                double fpcntHeight = (intensities[maxIntensityIndex] - baselineIntensity) / 20 + baselineIntensity;
+                int iBeginning = 0;
+                for (int i = maxIntensityIndex - 1; i >= 0; i--)
+                {
+                    if (intensities[i] < fpcntHeight)
+                    {
+                        iBeginning = i;
+                        break;
+                    }
+                }
+                int len = intensities.Length;
+                int iTail = len - 1;
+                for (int i = maxIntensityIndex + 1; i < len; i++)
+                {
+                    if (intensities[i] < fpcntHeight)
+                    {
+                        iTail = i;
+                        break;
+                    }
+                }
+                fwfpcnt = Math.Max(fwfpcnt, iTail - iBeginning);
+            }
+
+                _widthDataWings = (int)(FullWidthHalfMax * 2);
 
             if (_widthDataWings > 0)
             {

CrawdadSharp/SlimCrawPeak.cs

@@ -7,6 +7,7 @@ public class SlimCrawPeak
         public int len;
         public float fwhm;
         public bool fwhm_calculated_ok;
+        public float fwfpct;
         public float bg_area;
         public float raw_area; // total area under the curve, including background
         public float peak_area;