# HG changeset patch
# User Daniel O'Connor <darius@dons.net.au>
# Date 1312946437 -34200
# Node ID 37d6ceb4850fbe0467acfff2df8a1045f17a4ab4
# Parent  55c8dae6d1dbceb43c1fd12fa49c272603bfe604
Add helper functions for SCPI.

diff -r 55c8dae6d1db -r 37d6ceb4850f scpi.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scpi.py	Wed Aug 10 12:50:37 2011 +0930
@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2011
+#      Daniel O'Connor <darius@dons.net.au>.  All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+
+import exceptions
+import numpy
+
+def bindecode(data, header = '', dtype = numpy.float32):
+    '''Decode binary data, returns numpy array'''
+    if data[0:len(header)] != header:
+        raise exceptions.ValueError('data header incorrect')
+    ofs = len(header)
+    if data[ofs] != '#':
+        raise exceptions.ValueError('data length header incorrect')
+    dlenlen = int(data[ofs + 1])
+    dlen = int(data[ofs + 2:ofs + dlenlen + 2])
+    if len(data) != len(header) + dlen + 2 + dlenlen:
+        raise exceptions.ValueError('length mismatch, header says %d, actually got %d bytes' % (len(header) + dlen + 2 + dlenlen, len(data)))
+    return numpy.frombuffer(data[len(header) + 2 + dlenlen:], dtype = dtype)
+
+def ascdecode(data, dtype = numpy.float32):
+    '''Decode ASCII data, returns numpy array'''
+    return numpy.fromstring(data, dtype = dtype, sep = ',')
+