updated lin_reg with additional particular solutions which now include, x and

y intercepts, y(mean(x)), weighted y(weighted_mean(x)), distance of weighted
mean solution from the mean

1 files changed, 13 insertions, 4 deletions

diff --git a/lin_reg.awk b/lin_reg.awk
index 28f94a7..7e71804 100644
--- a/lin_reg.awk
+++ b/lin_reg.awk
@@ -74,6 +74,12 @@ NF > 0 {
                 a_err_den[x,y] = count[x,y]*b_err_den[x,y]
                 if (a_err_den[x,y])
                     a_err[x,y] = sqrt(sum2[x]/count[x,y])*b_err[x,y]
+
+                # weighted mean, from HP-20S manual
+                xw[x,y] = sum_xy[x,y]/sum[y]
+                yw[x,y] = b[x,y]*xw[x,y] + a[x,y]
+                xw_dist[x,y] = (xw[x,y] - mean[x])
+                yw_dist[x,y] = b[x,y]*(xw[x,y] - mean[x])
             }
         }
         else
@@ -85,12 +91,15 @@ END {
     for (y=1; y<=nf_max; y++) {
         for (x=1; x<=nf_max; x++) {
             if (x != y && r[x,y]) {
-                printf(OFMT OFS "(%s)" OFS " = (" OFMT " +/- " OFMT ")(%s)" OFS " + (" OFMT " +/- " OFMT ") \t [" OFMT "," OFMT "] \t [" OFMT "," OFMT "]" ORS,
+                printf(OFMT OFS "(%s)" OFS " = (" OFMT " +/- " OFMT ")(%s)" OFS " + (" OFMT " +/- " OFMT ")",
                     (r[x,y]*r[x,y]),
                     header[y], b[x,y], b_err[x,y],
-                    header[x], a[x,y], a_err[x,y],
-                    mean[x], b[x,y]*(mean[x]) + a[x,y],
-                    sum_xy[x,y]/sum[y], b[x,y]*(sum_xy[x,y]/sum[y]) + a[x,y])
+                    header[x], a[x,y], a_err[x,y])
+                printf("  [" OFMT "," OFMT "][" OFMT "," OFMT "]  [" OFMT "," OFMT "]",
+                    0, a[x,y], (-1.0*a[x,y]/b[x,y]), 0,
+                    mean[x], b[x,y]*(mean[x]) + a[x,y])
+                printf("  [" OFMT "," OFMT "]", xw[x,y], yw[x,y])
+                printf("  [" OFMT "]" ORS, sqrt(xw_dist[x,y]*xw_dist[x,y] + yw_dist[x,y]*yw_dist[x,y]))
             }
         }
     }