From 5a8207c9d18ff88d6c762b8c57d57d9c4a2ff8db Mon Sep 17 00:00:00 2001
From: Trygve Laugstøl <trygvis@inamo.no>
Date: Sat, 8 Jul 2017 22:35:29 +0200
Subject: o Start on some electronics engineering code.

---
 ee/__init__.py | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 ee/__init__.py

(limited to 'ee/__init__.py')

diff --git a/ee/__init__.py b/ee/__init__.py
new file mode 100644
index 0000000..5c26c0a
--- /dev/null
+++ b/ee/__init__.py
@@ -0,0 +1,109 @@
+import sympy
+import numpy as np
+
+__all__ = [
+  'read_ltspice_raw'
+]
+
+class LtSpiceRaw(object):
+  def __init__(self, variables, values):
+    self.variables = variables
+    self.values = values
+
+  def get_values(self, variable):
+    v = [v for v in self.variables if v.expression == variable]
+    if len(v) != 1:
+        raise Error('Unknown variable: ' + str(variable))
+    return self.values[v[0].idx]
+
+class LtSpiceVariable(object):
+  def __init__(self, idx, expression, kind):
+    self.idx = idx
+    self.expression = expression
+    self.kind = kind
+
+class LtSpiceReader(object):
+
+  def __init__(self, f):
+    self.f = f
+    self.mode = 'header'
+    self.headers = {}
+
+  def read_header(self, line):
+    sep = line.find(':')
+    key = line[0:sep]
+    value = line[sep + 1:].strip()
+
+#    print("key='{}', value='{}'".format(key, str(value)))
+
+    if key == 'Binary':
+      self.set_binary_mode()
+    elif key == 'Variables':
+      self.no_variables = int(self.headers['No. Variables'])
+      self.variables = []
+      self.mode = 'variables'
+    else:
+      self.headers[key] = value
+
+  def read_variable(self, line):
+    parts = line.split('\t')
+    idx = int(parts[1])
+    expression = parts[2]
+    kind = parts[3]
+    self.variables.append(LtSpiceVariable(idx, expression, kind))
+
+    if len(self.variables) == self.no_variables:
+      self.mode = 'header'
+
+  def set_binary_mode(self):
+    self.mode = 'binary'
+
+  def read_binary(self):
+    pos = self.f.tell()
+    # Skip an extra '\0'
+    self.f.seek(pos + 1)
+    no_points = int(self.headers['No. Points'])
+    no_variables = int(self.headers['No. Variables'])
+#    print("variables={}, no_points={}, pos={}".format(no_variables, no_points, pos))
+    self.values = vs = np.zeros((no_variables, no_points))
+    for p in range(no_points):
+      vs[0][p] = np.fromfile(self.f, count=1, dtype='float64')
+      pointdata = np.fromfile(self.f, count=no_variables - 1, dtype='float32')
+#      print("value={:0=0.15e}".format(vs[0][p]))
+      for v in range(1, no_variables):
+#        print("p={}, v={}".format(p, v))
+#        print("  value={:0=0.15e}".format(pointdata[v - 1]))
+        vs[v][p] = pointdata[v - 1]
+
+  def read(self):
+    while True:
+      line = self.f.readline();
+
+      if len(line) == 0:
+        break
+
+      if line[0] == 0:
+        line = line[1:]
+      if line[-1] == 10:
+        line = line[:-1]
+#    print("len(line)={}, line={}".format(len(line), str(line)))
+      line = str(line, encoding="utf-16")
+
+      if self.mode == 'header':
+        self.read_header(line)
+      elif self.mode == 'variables':
+        self.read_variable(line)
+
+      # The binary data can't be read with readline()
+      if self.mode == 'binary':
+#        self.f.read()
+        self.read_binary()
+        break
+
+    return LtSpiceRaw(self.variables, self.values)
+
+def read_ltspice_raw(filename):
+
+  with open(filename, mode="rb") as f:
+    r = LtSpiceReader(f)
+    return r.read()
-- 
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