0.1.1 SparseMatrix

Author: RobTillaart

libraries/SparseMatrix/README.md

@@ -32,6 +32,8 @@ Relates to https://github.com/RobTillaart/distanceTable
 The implementation is based on 3 arrays holding ``` x, y, value``` where value is float.
 In the future other datatypes should be possible.
 
+#### Performance
+
 The elements are not kept sorted or indexed so optimizations are possible
 but not investigated yet.
 
@@ -43,10 +45,15 @@ Parameter is the maximum number of elements in the sparse matrix.
 - **uint8_t size()** maximum number of elements.
 - **uint8_t count()** current number of elements in the matrix.
 - **float sum()** sum of all elements ( > 0 ) in the matrix.
+- **void clear()** resets the matrix to all zero's again.
 - **bool set(uint8_t x, uint8_t y, float value)** gives an element in the matrix a value.
 If the value is set to zero, it is removed from the internal store.
 Returns false if the internal store is full, true otherwise.
 - **float get(uint8_t x, uint8_t y)** returns the value in the matrix. 
+- **bool add(uint8_t x, uint8_t y, float value)** adds a value to an element in the matrix.
+If needed a new internal element is created. 
+If the sum is zero, the element is removed from the internal store.
+Returns false if the internal store is full, true otherwise.
 
 
 ## Future
@@ -61,23 +68,19 @@ Returns false if the internal store is full, true otherwise.
   - 2D histogram e.g. temperature vs humidity
   - N queens game.
 - investigate optimizations.
-- should **set()** return the number of free places?
+- should **set()** and **add()** return the number of free places?
   - no hard code and more informative than just a bool.
+- can **set()** and **add()** be merged?
 - add link in distanceTable repo
 - uint16_t size for larger platforms.
   - max matrix still 255 x 255 but more elements <> 0.
 
 
 #### new functions
 
-- **float add(uint8_t x, uint8_t y, float value)** adds value to the x,y position.
-  - add or remove an internal element if needed,
-  - functional **set(x,y, get(x,y) + value)**
-- **void clear()** sets all elements to zero again. 
-  - \_count = 0; should be sufficient.
-- walking through the elements?
+- walk through the elements?
   - first -> next;  last -> prev.
-  
+
 
 #### won't
 

libraries/SparseMatrix/SparseMatrix.cpp

@@ -1,12 +1,15 @@
 //
 //    FILE: SparseMatrix.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.0
+// VERSION: 0.1.1
 //    DATE: 2022-07-12
 // PURPOSE: Arduino library for sparse matrices
 //
 //  HISTORY:
 //  0.1.0  2022-07-12  initial version
+//  0.1.1  2022-07-13  add clear();
+//                     add add(x, y, value);
+//                     fix set(x, y, 0);
 
 
 #include "SparseMatrix.h"
@@ -21,6 +24,7 @@ SparseMatrix::SparseMatrix(uint8_t sz)
   _value = (float *)   malloc(sz * sizeof(float));
   //  catch malloc error
   if (_x && _y && _value) return;
+  //  if malloc error set size to zero.
   _size = 0;
 }
 
@@ -44,6 +48,13 @@ uint8_t SparseMatrix::count()
   return _count;
 }
 
+
+void SparseMatrix::clear()
+{
+  _count = 0;
+}
+
+
 float SparseMatrix::sum()
 {
   float _sum = 0;
@@ -70,17 +81,54 @@ bool SparseMatrix::set(uint8_t x, uint8_t y, float value)
       _count--;
       //  move last element
       //  efficiency is not a requirement yet.
-      _x[pos] = _x[_count];
-      _y[pos] = _y[_count];
-      _value[pos] = _value[_count];
+      if (_count > 0)
+      {
+        _x[pos]     = _x[_count];
+        _y[pos]     = _y[_count];
+        _value[pos] = _value[_count];
+      }
+    }
+    return true;
+  }
+
+  //  does not exist => new element ?
+  if (value == 0) return true;
+  if (_count >= _size) return false;
+  _x[_count]     = x;
+  _y[_count]     = y;
+  _value[_count] = value;
+  _count++;
+  return true;
+}
+
+
+bool SparseMatrix::add(uint8_t x, uint8_t y, float value)
+{
+  int pos = findPos(x, y);
+  //  existing element
+  if (pos > -1)
+  {
+    _value[pos] += value;
+    if (_value[pos] == 0.0)
+    {
+      _count--;
+      //  move last element
+      //  efficiency is not a requirement yet.
+      if (_count > 0)
+      {
+        _x[pos]     = _x[_count];
+        _y[pos]     = _y[_count];
+        _value[pos] = _value[_count];
+      }
     }
     return true;
   }
 
-  //  new element
+  //  does not exist => new element ?
+  if (value == 0) return true;
   if (_count >= _size) return false;
-  _x[_count] = x;
-  _y[_count] = y;
+  _x[_count]     = x;
+  _y[_count]     = y;
   _value[_count] = value;
   _count++;
   return true;

libraries/SparseMatrix/SparseMatrix.h

@@ -2,15 +2,15 @@
 //
 //    FILE: SparseMatrix.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.0
+// VERSION: 0.1.1
 //    DATE: 2022-07-12
 // PURPOSE: Arduino library for sparse matrices
 //
 
 
 #include "Arduino.h"
 
-#define SPARSEMATRIX_LIB_VERSION        (F("0.1.0"))
+#define SPARSEMATRIX_LIB_VERSION        (F("0.1.1"))
 
 
 class SparseMatrix
@@ -22,10 +22,14 @@ class SparseMatrix
   uint8_t  size();
   uint8_t  count();
   float    sum();
+  void     clear();
+
 
   //  returns false if no slots free
   //  could return # free slots?
   bool     set(uint8_t x, uint8_t y, float value);
+  //  adds value to element x,y
+  bool     add(uint8_t x, uint8_t y, float value);
   float    get(uint8_t x, uint8_t y);
 
 

libraries/SparseMatrix/examples/sparse_matrix_demo/sparse_matrix_demo.ino

@@ -29,7 +29,6 @@ void setup()
     bool b = sm.set(x, y, value);  // check full
     if (b) Serial.print('.');
   }
-
   Serial.println();
   dump(10, 10);
 
@@ -38,6 +37,32 @@ void setup()
     sm.set(3, y, 0);
   }
   dump(10, 10);
+
+  for (int y = 0; y < 10; y++)
+  {
+    bool b = sm.add(0, y, -1);
+    if (b == false) Serial.print('e');
+  }
+  Serial.println();
+  dump(10, 10);
+
+  sm.clear();
+  Serial.println();
+  dump(10, 10);
+
+  for (int y = 0; y < 10; y++)
+  {
+    sm.add(y, y, 5);
+  }
+  Serial.println();
+  dump(10, 10);
+
+  for (int y = 0; y < 10; y++)
+  {
+    sm.add(y, y, -5);
+  }
+  Serial.println();
+  dump(10, 10);
 }
 
 

libraries/SparseMatrix/examples/sparse_matrix_performance/performance_0.1.1.txt

@@ -0,0 +1,13 @@
+sparse_matrix_performance.ino
+20
+0
+
+set 20x :	272
+redo 20x :	224
+full 20x :	368
+add 20x :	444
+get 20x :	232
+9.00
+sum 20x :	156
+clr 20x :	4
+

libraries/SparseMatrix/examples/sparse_matrix_performance/sparse_matrix_performance.ino

@@ -1,7 +1,7 @@
 //
 //    FILE: sparse_matrix_performance.ino
 //  AUTHOR: Rob Tillaart
-// PURPOSE: demo
+// PURPOSE: performance measurement functions
 
 
 #include  "SparseMatrix.h"
@@ -54,6 +54,16 @@ void setup()
   Serial.println(stop - start);
   delay(100);
 
+  start = micros();
+  for (int i = 0; i < 20; i++)
+  {
+    sm.add(i, i, 5);
+  }
+  stop = micros();
+  Serial.print("add 20x :\t");
+  Serial.println(stop - start);
+  delay(100);
+
   volatile float f;
   start = micros();
   for (int i = 0; i < 20; i++)
@@ -72,6 +82,16 @@ void setup()
   Serial.print("sum 20x :\t");
   Serial.println(stop - start);
   delay(100);
+
+  start = micros();
+  for (int i = 0; i < 20; i++)
+  {
+    sm.clear();
+  }
+  stop = micros();
+  Serial.print("clr 20x :\t");
+  Serial.println(stop - start);
+  delay(100);
 }
 
 

libraries/SparseMatrix/keywords.txt

@@ -7,9 +7,11 @@ SparseMatrix	KEYWORD1
 size	KEYWORD2
 count	KEYWORD2
 sum	KEYWORD2
+clear	KEYWORD2
 
 get	KEYWORD2
 set	KEYWORD2
+add	KEYWORD2
 
 
 # Constants (LITERAL1)

libraries/SparseMatrix/library.json

@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/SparseMatrix.git"
   },
-  "version": "0.1.0",
+  "version": "0.1.1",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*",

libraries/SparseMatrix/library.properties

@@ -1,5 +1,5 @@
 name=SparseMatrix
-version=0.1.0
+version=0.1.1
 author=Rob Tillaart <[email protected]>
 maintainer=Rob Tillaart <[email protected]>
 sentence=Arduino library for sparse matrices.

libraries/SparseMatrix/test/unit_test_001.cpp

@@ -52,9 +52,17 @@ unittest(test_set)
   for (int i = 0; i < 10; i++)
   {
     assertTrue(sm.set(i, i, 1.0 * i * i));
-    assertEqual(i+1, sm.count());
+    assertEqual(i, sm.count());
   }
-  assertFalse(sm.set(3,4,5));   //  don't fit any more...
+  assertTrue(sm.set(3, 4, 5));
+  assertFalse(sm.set(5, 4, 5));   //  don't fit any more...
+
+  //  do not set new element to zero 
+  sm.clear();
+  assertEqual(0, sm.count());
+
+  sm.set(1, 2, 0);
+  assertEqual(0, sm.count());
 }
 
 
@@ -66,7 +74,6 @@ unittest(test_get)
     assertTrue(sm.set(i, i, 1.0 * i * i));
     assertEqualFloat(1.0 * i * i, sm.get(i, i), 0.001);
   }
-  assertFalse(sm.set(3,4,5));   //  don't fit any more...
 }
 
 
@@ -81,6 +88,28 @@ unittest(test_sum)
 }
 
 
+unittest(test_add)
+{
+  SparseMatrix sm(10);
+  for (int i = 0; i < 10; i++)
+  {
+    assertTrue(sm.add(i, i, 1.0 * i * i));
+    assertEqualFloat(1.0 * i * i, sm.get(i, i), 0.001);
+  }
+  for (int i = 0; i < 10; i++)
+  {
+    assertTrue(sm.add(i, i, 1.0 * i * i));
+    assertEqualFloat(2.0 * i * i, sm.get(i, i), 0.001);
+  }
+  for (int i = 0; i < 10; i++)
+  {
+    assertTrue(sm.add(i, i, -2.0 * i * i));
+    assertEqualFloat(0, sm.get(i, i), 0.001);
+  }
+  assertEqual(0, sm.count());
+}
+
+
 unittest_main()