Plot scatter rather than coordinates. Alas, this doesn't solve the

aspect-ratio problem.

1 files changed, 9 insertions, 7 deletions

diff --git a/gpsprobe b/gpsprobe
index a3066f5a..f914f5ce 100755
--- a/gpsprobe
+++ b/gpsprobe
@@ -190,6 +190,7 @@ if __name__ == '__main__':
             def d(a, b): return sqrt((a[0] - b[0])**2 + (a[1] - b[1])**2)
             fixes.sort(lambda x, y: cmp(d(centroid, x), d(centroid, y)))
             print "Probable error is %f meters." % gps.EarthDistance(centroid, fixes[len(fixes)/2])
+            recentered = map(lambda fix: (fix[0]-centroid[0], fix[1]-centroid[1]), fixes)  
             sys.stdout.write("Writing fix scattergram to %s..." % outfile)
             fp = open(outfile,"w")
             fp.write("# This is a gnuplot script generated by gpsprobe.\n")
@@ -197,22 +198,23 @@ if __name__ == '__main__':
             fp.write('set format x "%2.6f"\n')
             fp.write('set format y "%2.6f"\n')
             fp.write('set key below\n')
-            fp.write('set xlabel \'Longitude\'\n')
-            fp.write('set ylabel \'Latitude\' 6  # Put it right over the Y axis\n')
+            fp.write('set size ratio -1\n')
+            fp.write('set xlabel \'Longitude scatter from %f\'\n' % centroid[1])
+            fp.write('set ylabel \'Latitude scatter from %f\' 6  # Put it right over the Y axis\n' % centroid[0])
             fp.write('centroidx=%f\n' % centroid[0])
             fp.write('centroidy=%f\n' % centroid[1])
             fp.write('cep=%f\n' % d(centroid, fixes[len(fixes)/2]))
             fp.write('set parametric\n')
             fp.write('set trange [0:2*pi]\n')
-            fp.write('cx(t, r) = sin(t)*r+centroidx\n')
-            fp.write('cy(t, r) = cos(t)*r+centroidy\n')
+            fp.write('cx(t, r) = sin(t)*r\n')
+            fp.write('cy(t, r) = cos(t)*r\n')
             fp.write('chlen = cep/10\n')
-            fp.write("set arrow from centroidx-chlen,centroidy to centroidx+chlen,centroidy nohead\n")
-            fp.write("set arrow from centroidx,centroidy-chlen to centroidx,centroidy+chlen nohead\n")
+            fp.write("set arrow from -chlen,0 to chlen,0 nohead\n")
+            fp.write("set arrow from 0,-chlen to 0,chlen nohead\n")
             fp.write('plot "-" using 1:2 title "%d GPS fixes", cx(t, cep),cy(t, cep) title "CEP (50%%)"\n' % len(fixes))
             fp.write("#\n")
             fp.write("# Lat	Lon\n")
-            for (lat, lon) in fixes:
+            for (lat, lon) in recentered:
                 fp.write("  %f	%f\n" % (lat, lon))
             fp.write("end\n")
             fp.write("pause -1\n")