From e6adaad90462fbc03663cc81d2be3a39f35dc8cb Mon Sep 17 00:00:00 2001
From: Jacob Gilbert <mrjacobagilbert@gmail.com>
Date: Wed, 7 Feb 2018 09:00:01 -0800
Subject: runtime: address floating point roundoff concerns in num_to_str() in
eng_notation - attempt 2
---
gnuradio-runtime/python/gnuradio/eng_notation.py | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
(limited to 'gnuradio-runtime/python/gnuradio/eng_notation.py')
diff --git a/gnuradio-runtime/python/gnuradio/eng_notation.py b/gnuradio-runtime/python/gnuradio/eng_notation.py
index d23f9005f0..12332aef7d 100644
--- a/gnuradio-runtime/python/gnuradio/eng_notation.py
+++ b/gnuradio-runtime/python/gnuradio/eng_notation.py
@@ -36,29 +36,30 @@ scale_factor['p'] = 1e-12
scale_factor['f'] = 1e-15
scale_factor['a'] = 1e-18
-def num_to_str (n):
+def num_to_str (n, precision=6):
'''Convert a number to a string in engineering notation. E.g., 5e-9 -> 5n'''
m = abs(n)
+ format_spec = '%.' + repr(int(precision)) + 'g'
if m >= 1e9:
- return "%gG" % (n * 1e-9)
+ return '%sG' % float(format_spec % (n * 1e-9))
elif m >= 1e6:
- return "%gM" % (n * 1e-6)
+ return '%sM' % float(format_spec % (n * 1e-6))
elif m >= 1e3:
- return "%gk" % (n * 1e-3)
+ return '%sk' % float(format_spec % (n * 1e-3))
elif m >= 1:
- return "%g" % (n)
+ return '%s' % float(format_spec % (n))
elif m >= 1e-3:
- return "%gm" % (n * 1e3)
+ return '%sm' % float(format_spec % (n * 1e3))
elif m >= 1e-6:
- return "%gu" % (n * 1e6) # where's that mu when you need it (unicode?)
+ return '%su' % float(format_spec % (n * 1e6))
elif m >= 1e-9:
- return "%gn" % (n * 1e9)
+ return '%sn' % float(format_spec % (n * 1e9))
elif m >= 1e-12:
- return "%gp" % (n * 1e12)
+ return '%sp' % float(format_spec % (n * 1e12))
elif m >= 1e-15:
- return "%gf" % (n * 1e15)
+ return '%sf' % float(format_spec % (n * 1e15))
else:
- return "%g" % (n)
+ return '%s' % float(format_spec % (n))
def str_to_num (value):
--
cgit v1.2.3