mathutil: Move coordinate_descent() to new file

Add a new python file (mathutil.py) and move the coordinate_descent()
code to it.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

4 files changed, 45 insertions, 39 deletions

diff --git a/klippy/extras/bed_tilt.py b/klippy/extras/bed_tilt.py
index f7e61052..a6254a29 100644
--- a/klippy/extras/bed_tilt.py
+++ b/klippy/extras/bed_tilt.py
@@ -4,7 +4,7 @@
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import logging
-import probe
+import probe, mathutil
 
 class BedTilt:
     def __init__(self, config):
@@ -73,7 +73,8 @@ class BedTiltCalibrate:
             for pos in positions:
                 total_error += adjusted_height(pos, params)**2
             return total_error
-        new_params = probe.coordinate_descent(params.keys(), params, errorfunc)
+        new_params = mathutil.coordinate_descent(
+            params.keys(), params, errorfunc)
         logging.info("Calculated bed_tilt parameters: %s", new_params)
         for pos in positions:
             logging.info("orig: %s new: %s", adjusted_height(pos, params),
diff --git a/klippy/extras/delta_calibrate.py b/klippy/extras/delta_calibrate.py
index b65a7815..57ae8f09 100644
--- a/klippy/extras/delta_calibrate.py
+++ b/klippy/extras/delta_calibrate.py
@@ -4,7 +4,7 @@
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import math, logging
-import probe, delta
+import probe, delta, mathutil
 
 class DeltaCalibrate:
     def __init__(self, config):
@@ -51,7 +51,7 @@ class DeltaCalibrate:
                 x, y, z = delta.get_position_from_stable(spos, params)
                 total_error += (z - self.probe_z_offset)**2
             return total_error
-        new_params = probe.coordinate_descent(
+        new_params = mathutil.coordinate_descent(
             adj_params, params, delta_errorfunc)
         logging.info("Calculated delta_calibrate parameters: %s", new_params)
         for spos in positions:
diff --git a/klippy/extras/probe.py b/klippy/extras/probe.py
index 70cc2a1d..4113a263 100644
--- a/klippy/extras/probe.py
+++ b/klippy/extras/probe.py
@@ -3,7 +3,6 @@
 # Copyright (C) 2017-2018  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
-import logging
 import pins, homing
 
 class PrinterProbe:
@@ -137,39 +136,5 @@ class ProbePointsHelper:
         if success:
             self.callback.finalize(self.results)
 
-# Helper code that implements coordinate descent
-def coordinate_descent(adj_params, params, error_func):
-    # Define potential changes
-    params = dict(params)
-    dp = {param_name: 1. for param_name in adj_params}
-    # Calculate the error
-    best_err = error_func(params)
-
-    threshold = 0.00001
-    rounds = 0
-
-    while sum(dp.values()) > threshold and rounds < 10000:
-        rounds += 1
-        for param_name in adj_params:
-            orig = params[param_name]
-            params[param_name] = orig + dp[param_name]
-            err = error_func(params)
-            if err < best_err:
-                # There was some improvement
-                best_err = err
-                dp[param_name] *= 1.1
-                continue
-            params[param_name] = orig - dp[param_name]
-            err = error_func(params)
-            if err < best_err:
-                # There was some improvement
-                best_err = err
-                dp[param_name] *= 1.1
-                continue
-            params[param_name] = orig
-            dp[param_name] *= 0.9
-    logging.info("Coordinate descent best_err: %s  rounds: %d", best_err, rounds)
-    return params
-
 def load_config(config):
     return PrinterProbe(config)
diff --git a/klippy/mathutil.py b/klippy/mathutil.py
new file mode 100644
index 00000000..d8df3539
--- /dev/null
+++ b/klippy/mathutil.py
@@ -0,0 +1,40 @@
+# Simple math helper functions
+#
+# Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+import logging
+
+# Helper code that implements coordinate descent
+def coordinate_descent(adj_params, params, error_func):
+    # Define potential changes
+    params = dict(params)
+    dp = {param_name: 1. for param_name in adj_params}
+    # Calculate the error
+    best_err = error_func(params)
+
+    threshold = 0.00001
+    rounds = 0
+
+    while sum(dp.values()) > threshold and rounds < 10000:
+        rounds += 1
+        for param_name in adj_params:
+            orig = params[param_name]
+            params[param_name] = orig + dp[param_name]
+            err = error_func(params)
+            if err < best_err:
+                # There was some improvement
+                best_err = err
+                dp[param_name] *= 1.1
+                continue
+            params[param_name] = orig - dp[param_name]
+            err = error_func(params)
+            if err < best_err:
+                # There was some improvement
+                best_err = err
+                dp[param_name] *= 1.1
+                continue
+            params[param_name] = orig
+            dp[param_name] *= 0.9
+    logging.info("Coordinate descent best_err: %s  rounds: %d", best_err, rounds)
+    return params