1 files changed, 71 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/eng_notation.py b/gnuradio-core/src/python/gnuradio/eng_notation.py
new file mode 100644
index 0000000000..72cd8931eb
--- /dev/null
+++ b/gnuradio-core/src/python/gnuradio/eng_notation.py
@@ -0,0 +1,71 @@
+#
+# Copyright 2003 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+# 
+
+scale_factor = {}
+scale_factor['E'] = 1e18
+scale_factor['P'] = 1e15
+scale_factor['T'] = 1e12
+scale_factor['G'] = 1e9
+scale_factor['M'] = 1e6
+scale_factor['k'] = 1e3
+scale_factor['m'] = 1e-3
+scale_factor['u'] = 1e-6
+scale_factor['n'] = 1e-9
+scale_factor['p'] = 1e-12
+scale_factor['f'] = 1e-15
+scale_factor['a'] = 1e-18
+
+def num_to_str (n):
+    '''Convert a number to a string in engineering notation.  E.g., 5e-9 -> 5n'''
+    m = abs(n)
+    if m >= 1e9:
+        return "%gG" % (n * 1e-9)
+    elif m >= 1e6:
+        return "%gM" % (n * 1e-6)
+    elif m >= 1e3:
+        return "%gk" % (n * 1e-3)
+    elif m >= 1:
+        return "%g" % (n)
+    elif m >= 1e-3:
+        return "%gm" % (n * 1e3)
+    elif m >= 1e-6:
+        return "%gu" % (n * 1e6)        # where's that mu when you need it (unicode?)
+    elif m >= 1e-9:
+        return "%gn" % (n * 1e9)
+    elif m >= 1e-12:
+        return "%gp" % (n * 1e12)
+    elif m >= 1e-15:
+        return "%gf" % (n * 1e15)
+    else:
+        return "%g" % (n)
+
+
+def str_to_num (value):
+    '''Convert a string in engineering notation to a number.  E.g., '15m' -> 15e-3'''
+    try:
+        scale = 1.0
+        suffix = value[-1]
+        if scale_factor.has_key (suffix):
+            return float (value[0:-1]) * scale_factor[suffix]
+        return float (value)
+    except:
+        raise RuntimeError (
+            "Invalid engineering notation value: %r" % (value,))