commit df79d11945cc41373e71a1531d258748d2aad703
author Austin Schuh <austin.linux@gmail.com> Sat Oct 15 21:25:32 2016 -0700
committer Austin Schuh <austin.linux@gmail.com> Sat Oct 29 13:51:10 2016 -0700
tree 64013dadb30d0a968c7d08c2c74d3cb9c9635568
parent 94a5237117053319b52d603181f13388e720696e

Converted Eigen << to direct assignment.

For a Cortex-M4, this results in significantly fewer instructions.
I have no idea why.

Change-Id: Ic398bdf240302d941d9ffb12f4eaa081ecd36080

frc971/control_loops/drivetrain/drivetrain.cc

diff --git a/frc971/control_loops/drivetrain/drivetrain.cc b/frc971/control_loops/drivetrain/drivetrain.cc
index 5757b58..651976e 100644
--- a/frc971/control_loops/drivetrain/drivetrain.cc
+++ b/frc971/control_loops/drivetrain/drivetrain.cc
@@ -140,7 +140,7 @@
       // z accel is down
       // x accel is the front of the robot pointed down.
       Eigen::Matrix<double, 1, 1> Y;
-      Y << angle;
+      Y(0, 0) = angle;
       down_estimator_.Correct(Y);
     }
 
@@ -148,7 +148,7 @@
         "New IMU value from ADIS16448, rate is %f, angle %f, fused %f, bias "
         "%f\n",
         rate, angle, down_estimator_.X_hat(0, 0), down_estimator_.X_hat(1, 0));
-    down_U_ << rate;
+    down_U_(0, 0) = rate;
   }
   down_estimator_.UpdateObserver(down_U_);
 
@@ -256,7 +256,8 @@
   // Voltage error.
 
   Eigen::Matrix<double, 2, 1> U;
-  U << last_left_voltage_, last_right_voltage_;
+  U(0, 0) = last_left_voltage_;
+  U(1, 0) = last_right_voltage_;
   last_left_voltage_ = left_voltage;
   last_right_voltage_ = right_voltage;
 

frc971/control_loops/python/control_loop.py

diff --git a/frc971/control_loops/python/control_loop.py b/frc971/control_loops/python/control_loop.py
index 951a114..d6bd85f 100644
--- a/frc971/control_loops/python/control_loop.py
+++ b/frc971/control_loops/python/control_loop.py
@@ -244,18 +244,10 @@
     """
     ans = ['  Eigen::Matrix<double, %d, %d> %s;\n' % (
         matrix.shape[0], matrix.shape[1], matrix_name)]
-    first = True
     for x in xrange(matrix.shape[0]):
       for y in xrange(matrix.shape[1]):
-        element = matrix[x, y]
-        if first:
-          ans.append('  %s << ' % matrix_name)
-          first = False
-        else:
-          ans.append(', ')
-        ans.append(str(element))
+        ans.append('  %s(%d, %d) = %s;\n' % (matrix_name, x, y, repr(matrix[x, y])))
 
-    ans.append(';\n')
     return ''.join(ans)
 
   def DumpPlantHeader(self):