1 files changed, 145 insertions, 0 deletions
diff --git a/src/ee/__init__.py b/src/ee/__init__.py
new file mode 100644
index 0000000..a22ecc6
--- /dev/null
+++ b/src/ee/__init__.py
@@ -0,0 +1,145 @@
+import numpy as np
+
+__all__ = [
+  'EeError',
+  'read_ltspice_raw'
+]
+
+class EeError(Exception):
+    pass
+
+class LtSpiceRaw(object):
+  def __init__(self, variables, values_first, values_rest):
+    self.variables = variables
+    self.values_first = values_first
+    self.values_rest = values_rest
+
+  def get_values(self, variable):
+    return self.values[variable.idx]
+
+  def get_variable(self, idx=None, expression=None):
+    if idx is not None:
+      return self.variables[idx]
+    if expression is not None:
+      v = [v for v in self.variables if v.expression == expression]
+      if len(v) != 1:
+          raise Exception('Unknown variable: ' + str(variable))
+      return v[0]
+    raise Exception('idx or expression must be given')
+
+  def to_pandas(self):
+    import pandas
+    data = []
+    for (i, v) in enumerate(self.values_first):
+      data.append(pandas.Series(v, dtype='float64'))
+
+    data = {}
+    for (i, v) in enumerate(self.values_first):
+      data[self.variables[i].expression] = v
+
+    return pandas.DataFrame(data = data)
+
+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 = {}
+    self.variables = []
+    self.values = []
+
+  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.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()
+    no_points = int(self.headers['No. Points'])
+    no_variables = int(self.headers['No. Variables'])
+
+#    print("no_points={}, no_variables={}".format(no_points, no_variables))
+
+    if True:
+      self.values = np.zeros((no_variables, no_points), dtype='float32')
+
+      for p in range(no_points):
+        self.values[0][p] = np.fromfile(self.f, count=1, dtype='float64')
+        row = np.fromfile(self.f, count=no_variables - 1, dtype='float32');
+        for v in range(0, len(row)):
+            self.values[v + 1][p] = row[v]
+    else:
+      self.values = np.zeros((no_points, no_variables), dtype='float64')
+
+      for p in range(no_points):
+        self.values[p][0] = np.fromfile(self.f, count=1, dtype='float64')
+        row = np.fromfile(self.f, count=no_variables - 1, dtype='float32');
+        for v in range(0, len(row)):
+            self.values[p][v + 1] = row[v]
+
+  def read(self):
+    while True:
+      line = self.f.readline();
+
+      if len(line) == 0:
+        break
+
+      self.f.read(1) # The data is utf16 encoded so read the extra null byte
+
+      # if this wasn't the last line .readline() includes the newline
+      if line[-1] == '\n' or line[-1] == 0x0a:
+        line = line[:-1]
+
+#      print("len(line)={}, line={}".format(len(line), str(line)))
+      line = line.decode(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
+
+    if len(self.variables) == 0:
+      raise Exception("Something didn't quite work when parsing file, no variables found")
+
+    return LtSpiceRaw(self.variables, self.values, [])
+
+def read_ltspice_raw(filename):
+
+  with open(filename, mode="rb") as f:
+    r = LtSpiceReader(f)
+    return r.read()