added SAX, final reports skeletons, screenshots

.gitignore

@@ -1,3 +1,2 @@
 obj_*
-*~
-code.pdf
+*~

Coursework-Reports/code.lyx

@@ -150,6 +150,21 @@ lstparams "breaklines=true,frame=tb,language=C,basicstyle={\\ttfamily},commentst
 \end_inset
 
 
+\end_layout
+
+\begin_layout Standard
+\begin_inset CommandInset include
+LatexCommand lstinputlisting
+filename "../Coursework/sax.h"
+lstparams "breaklines=true,frame=tb,language=C,basicstyle={\\ttfamily},commentstyle={\\color{commentgreen}\\itshape},keywordstyle={\\color{blue}},emphstyle={\\color{red}},stringstyle={\\color{red}},identifierstyle={\\color{cyan}},caption={SAX header file: z-normalise and stringify buffers}"
+
+\end_inset
+
+
+\begin_inset Newpage pagebreak
+\end_inset
+
+
 \end_layout
 
 \begin_layout Standard

Coursework-Reports/report.lyx

@@ -0,0 +1,169 @@
+#LyX 2.3 created this file. For more info see http://www.lyx.org/
+\lyxformat 544
+\begin_document
+\begin_header
+\save_transient_properties true
+\origin unavailable
+\textclass article
+\begin_preamble
+\usepackage{color}
+
+\definecolor{commentgreen}{RGB}{0,94,11}
+\end_preamble
+\use_default_options true
+\begin_modules
+customHeadersFooters
+\end_modules
+\maintain_unincluded_children false
+\language english
+\language_package default
+\inputencoding auto
+\fontencoding global
+\font_roman "default" "default"
+\font_sans "default" "default"
+\font_typewriter "default" "default"
+\font_math "auto" "auto"
+\font_default_family default
+\use_non_tex_fonts false
+\font_sc false
+\font_osf false
+\font_sf_scale 100 100
+\font_tt_scale 100 100
+\use_microtype false
+\use_dash_ligatures true
+\graphics default
+\default_output_format default
+\output_sync 0
+\bibtex_command default
+\index_command default
+\paperfontsize default
+\spacing single
+\use_hyperref true
+\pdf_title "IoT Aggregation Algorithm Coursework"
+\pdf_author "Andy Pack"
+\pdf_subject "IoT"
+\pdf_bookmarks true
+\pdf_bookmarksnumbered false
+\pdf_bookmarksopen false
+\pdf_bookmarksopenlevel 1
+\pdf_breaklinks true
+\pdf_pdfborder true
+\pdf_colorlinks false
+\pdf_backref false
+\pdf_pdfusetitle true
+\papersize default
+\use_geometry true
+\use_package amsmath 1
+\use_package amssymb 1
+\use_package cancel 1
+\use_package esint 1
+\use_package mathdots 1
+\use_package mathtools 1
+\use_package mhchem 1
+\use_package stackrel 1
+\use_package stmaryrd 1
+\use_package undertilde 1
+\cite_engine basic
+\cite_engine_type default
+\biblio_style plain
+\use_bibtopic false
+\use_indices false
+\paperorientation portrait
+\suppress_date false
+\justification true
+\use_refstyle 1
+\use_minted 0
+\index Index
+\shortcut idx
+\color #008000
+\end_index
+\leftmargin 1cm
+\topmargin 1.5cm
+\rightmargin 1cm
+\bottommargin 1.5cm
+\secnumdepth 3
+\tocdepth 3
+\paragraph_separation indent
+\paragraph_indentation default
+\is_math_indent 0
+\math_numbering_side default
+\quotes_style english
+\dynamic_quotes 0
+\papercolumns 1
+\papersides 1
+\paperpagestyle fancy
+\tracking_changes false
+\output_changes false
+\html_math_output 0
+\html_css_as_file 0
+\html_be_strict false
+\end_header
+
+\begin_body
+
+\begin_layout Left Header
+IoT Aggregation Algorithm Coursework
+\end_layout
+
+\begin_layout Left Footer
+November 2020
+\end_layout
+
+\begin_layout Right Footer
+Andy Pack / 6420013
+\end_layout
+
+\begin_layout Section
+Description
+\end_layout
+
+\begin_layout Section
+Specification
+\end_layout
+
+\begin_layout Section
+Implementation
+\end_layout
+
+\begin_layout Section
+Output
+\end_layout
+
+\begin_layout Standard
+\begin_inset Float figure
+placement h
+wide false
+sideways false
+status open
+
+\begin_layout Plain Layout
+\align center
+\begin_inset Graphics
+	filename SaxBy2,10Break.png
+	width 100col%
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Plain Layout
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+Demonstration of SAX aggregation with window size of 2 and alphabet of length
+ 10
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_body
+\end_document

Coursework-Reports/screenshot.lyx

@@ -0,0 +1,222 @@
+#LyX 2.3 created this file. For more info see http://www.lyx.org/
+\lyxformat 544
+\begin_document
+\begin_header
+\save_transient_properties true
+\origin unavailable
+\textclass article
+\begin_preamble
+\usepackage{color}
+
+\definecolor{commentgreen}{RGB}{0,94,11}
+\end_preamble
+\use_default_options true
+\begin_modules
+customHeadersFooters
+\end_modules
+\maintain_unincluded_children false
+\language english
+\language_package default
+\inputencoding auto
+\fontencoding global
+\font_roman "default" "default"
+\font_sans "default" "default"
+\font_typewriter "default" "default"
+\font_math "auto" "auto"
+\font_default_family default
+\use_non_tex_fonts false
+\font_sc false
+\font_osf false
+\font_sf_scale 100 100
+\font_tt_scale 100 100
+\use_microtype false
+\use_dash_ligatures true
+\graphics default
+\default_output_format default
+\output_sync 0
+\bibtex_command default
+\index_command default
+\paperfontsize default
+\spacing single
+\use_hyperref true
+\pdf_title "IoT Aggregation Algorithm Coursework"
+\pdf_author "Andy Pack"
+\pdf_subject "IoT"
+\pdf_bookmarks true
+\pdf_bookmarksnumbered false
+\pdf_bookmarksopen false
+\pdf_bookmarksopenlevel 1
+\pdf_breaklinks true
+\pdf_pdfborder true
+\pdf_colorlinks false
+\pdf_backref false
+\pdf_pdfusetitle true
+\papersize default
+\use_geometry true
+\use_package amsmath 1
+\use_package amssymb 1
+\use_package cancel 1
+\use_package esint 1
+\use_package mathdots 1
+\use_package mathtools 1
+\use_package mhchem 1
+\use_package stackrel 1
+\use_package stmaryrd 1
+\use_package undertilde 1
+\cite_engine basic
+\cite_engine_type default
+\biblio_style plain
+\use_bibtopic false
+\use_indices false
+\paperorientation portrait
+\suppress_date false
+\justification true
+\use_refstyle 1
+\use_minted 0
+\index Index
+\shortcut idx
+\color #008000
+\end_index
+\leftmargin 1cm
+\topmargin 1.5cm
+\rightmargin 1cm
+\bottommargin 1.5cm
+\secnumdepth 3
+\tocdepth 3
+\paragraph_separation indent
+\paragraph_indentation default
+\is_math_indent 0
+\math_numbering_side default
+\quotes_style english
+\dynamic_quotes 0
+\papercolumns 1
+\papersides 1
+\paperpagestyle fancy
+\tracking_changes false
+\output_changes false
+\html_math_output 0
+\html_css_as_file 0
+\html_be_strict false
+\end_header
+
+\begin_body
+
+\begin_layout Left Header
+IoT Aggregation Algorithm Coursework
+\end_layout
+
+\begin_layout Left Footer
+November 2020
+\end_layout
+
+\begin_layout Right Footer
+Andy Pack / 6420013
+\end_layout
+
+\begin_layout Standard
+\begin_inset Float figure
+wide false
+sideways false
+status open
+
+\begin_layout Plain Layout
+\align center
+\begin_inset Graphics
+	filename NonSaxAggregate.png
+	width 100col%
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Plain Layout
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+Demonstration of 4-into-1 aggregation taking place following moderate activity
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Float figure
+wide false
+sideways false
+status open
+
+\begin_layout Plain Layout
+\align center
+\begin_inset Graphics
+	filename NonSaxWithRed.png
+	width 100col%
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Plain Layout
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+Demonstration of both no aggregation for high activity (First output) and
+ tight 12-into-1 average for little activity (Last output), red LED on as
+ aggregation occurs
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Standard
+\begin_inset Float figure
+wide false
+sideways false
+status open
+
+\begin_layout Plain Layout
+\align center
+\begin_inset Graphics
+	filename SaxBy2,10Break.png
+	width 100col%
+
+\end_inset
+
+
+\end_layout
+
+\begin_layout Plain Layout
+\begin_inset Caption Standard
+
+\begin_layout Plain Layout
+Demonstration of SAX aggregation with window size of 2 and alphabet of length
+ 10
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_inset
+
+
+\end_layout
+
+\end_body
+\end_document

Coursework/buffer.h

@@ -44,8 +44,7 @@ aggregateBuffer(Buffer bufferIn, Buffer bufferOut, int groupSize)
 
     if(requiredGroups > bufferOut.length) // error check
     {
-        putFloat((float)bufferIn.length/groupSize);
-        printf(" length out buffer required, %i provided\n", bufferOut.length);
+        putFloat((float)bufferIn.length/groupSize); printf(" length out buffer required, %i provided\n", bufferOut.length);
         return;
     }
 

Coursework/coursework.c

@@ -4,10 +4,13 @@
 #define SD_THRESHOLD_SOME 400 // some activity, compress above, flatten below
 #define SD_THRESHOLD_LOTS 1000 // lots of activity, don't aggregate
 
-#define AGGREGATION_GROUP_SIZE 4 // group size to aggregate (4 in spec)
+#define AGGREGATION_GROUP_SIZE 2 // group size to aggregate (4 in spec)
 
 #define INITIAL_STATE true // whether begins running or not
 
+#define SAX // use sax aggregation and transform instead of simple average aggregation
+#define SAX_BREAKPOINTS 10 // number of characters to be used
+
 #include "contiki.h"
 
 #include <stdio.h> /* For printf() */
@@ -17,6 +20,7 @@
 #include "util.h" // for print methods
 #include "math.h"
 #include "buffer.h"
+#include "sax.h"
 
 static process_event_t event_buffer_full;
 
@@ -103,7 +107,11 @@ PROCESS_THREAD(aggregator_process, ev, data)
 
         Buffer fullBuffer = *(Buffer *)data;
         /*********************/
-        handleBufferRotation(&fullBuffer); // pass by reference, edited if lots of activity
+#ifdef SAX
+        handleSAXBufferRotation(&fullBuffer);
+#else
+        handleSimpleBufferRotation(&fullBuffer); // pass by reference, edited if lots of activity
+#endif
         freeBuffer(fullBuffer);
         /*********************/
     }
@@ -113,7 +121,7 @@ PROCESS_THREAD(aggregator_process, ev, data)
 /*---------------------------------------------------------------------------*/
 // Buffer filled with readings, process and aggregate
 void
-handleBufferRotation(Buffer *inBufferPtr)
+handleSimpleBufferRotation(Buffer *inBufferPtr)
 {
     printf("Buffer full, aggregating\n\n");
     
@@ -153,6 +161,31 @@ handleBufferRotation(Buffer *inBufferPtr)
         outBuffer.items[0] = sd.mean;
     }
     outBuffer.stats = sd; // final compressed buffer has pointer to stats for uncompressed data in case of further interest
+    inBuffer.stats = sd;
+    
+    /*********************/
+    handleFinalBuffer(outBuffer); // PASS FINAL BUFFER
+    freeBuffer(outBuffer); // RELEASE ITEMS
+    /*********************/
+}
+
+void
+handleSAXBufferRotation(Buffer *inBufferPtr)
+{
+    printf("Buffer full, SAX-ing\n\n");
+    
+    Buffer inBuffer = *inBufferPtr;
+    Buffer outBuffer; // OUTPUT BUFFER HOLDER
+    // above pointer is assigned a buffer in either of the below cases
+
+    int outLength = ceil((float)inBuffer.length/AGGREGATION_GROUP_SIZE); // CALCULATE NUMBER OF OUTPUT ELEMENTS
+    outBuffer = getBuffer(outLength); // CREATE OUTPUT BUFFER
+    
+    inBuffer.stats = calculateStdDev(inBuffer.items, inBuffer.length); // GET BUFFER STATISTICS
+    outBuffer.stats = inBuffer.stats;
+    
+    normaliseBuffer(inBuffer); // Z NORMALISATION
+    aggregateBuffer(inBuffer, outBuffer, AGGREGATION_GROUP_SIZE); // PAA
     
     /*********************/
     handleFinalBuffer(outBuffer); // PASS FINAL BUFFER
@@ -168,5 +201,12 @@ handleFinalBuffer(Buffer buffer)
     printBuffer(buffer);putchar('\n');
     printf("Mean: ");putFloat(buffer.stats.mean);putchar('\n');
     printf("Std Dev: ");putFloat(buffer.stats.std);putchar('\n');putchar('\n');
+    
+#ifdef SAX
+    char* saxString = stringifyBuffer(buffer);
+    printf("SAX: %s\n\n", saxString);
+    
+    free(saxString);
+#endif
 }
 /*---------------------------------------------------------------------------*/

Coursework/sax.h

@@ -0,0 +1,93 @@
+#ifndef _SAX_GUARD
+#define _SAX_GUARD
+
+#define SAX_CHAR_START 'a'
+
+#ifndef SAX_BREAKPOINTS
+    #define SAX_BREAKPOINTS 4
+#endif
+
+// Could have used a 2d array for breakpoints, index by number of breakpoints
+
+// Since the number of boundaries is known at compile-time, save these lookup calls by
+// defining as as constant 1D arrays
+
+#if SAX_BREAKPOINTS == 3
+    const float breakPoints[] = {-0.43, 0.43};
+#elif SAX_BREAKPOINTS == 4
+    const float breakPoints[] = {-0.67, 0, 0.67};
+#elif SAX_BREAKPOINTS == 5
+    const float breakPoints[] = {-0.84, -0.25, 0.25, 0.84};
+#elif SAX_BREAKPOINTS == 6
+    const float breakPoints[] = {-0.97, -0.43, 0, 0.43, 0.97};
+#elif SAX_BREAKPOINTS == 7
+    const float breakPoints[] = {-1.07, -0.57, -0.18, 0.18, 0.57, 1.07};
+#elif SAX_BREAKPOINTS == 8
+    const float breakPoints[] = {-1.15, -0.67, -0.32, 0, 0.32, 0.67, 1.15};
+#elif SAX_BREAKPOINTS == 9
+    const float breakPoints[] = {-1.22, -0.76, -0.43, -0.14, 0.14, 0.43, 0.76, 1.22};
+#elif SAX_BREAKPOINTS == 10
+    const float breakPoints[] = {-1.28, -0.84, -0.52, -0.25, 0, 0.25, 0.52, 0.84, 1.28};
+#else
+    #define SAX_BREAKPOINTS 4
+    const float breakPoints[] = {-0.67, 0, 0.67};
+#endif
+
+void
+normaliseBuffer(Buffer bufferIn) // z normalise buffer for SAX
+{
+    if(bufferIn.stats.std == 0) // error check
+    {
+        printf("Standard deviation of zero, unable to normalise\n");
+        return;
+    }
+
+    int i; // for group number
+    float *inputPtr = bufferIn.items; // cursor for full buffer
+    for(i = 0; i < bufferIn.length; i++)
+    {
+        *inputPtr = (*inputPtr - bufferIn.stats.mean) / bufferIn.stats.std;
+        
+        inputPtr++; // increment both cursors
+    }
+}
+
+char
+valueToSAXChar(float inputValue)
+{ 
+    float below, above;
+    int i;
+    for(i = 0; i < SAX_BREAKPOINTS; i++)
+    {
+        if(i == 0) // first iter, is less than first breakpoint
+        {
+            if(inputValue < breakPoints[i]) return SAX_CHAR_START + i;
+        }
+        else if(i == SAX_BREAKPOINTS - 1) // last iter, is more than last breakpoint
+        {
+            if(breakPoints[i - 1] < inputValue) return SAX_CHAR_START + i;
+        }
+        else // in between check interval of two breakpoints
+        {
+            if(breakPoints[i - 1] < inputValue < breakPoints[i]) return SAX_CHAR_START + i;
+        }
+    }
+    return '0';
+}
+
+char* // map buffer of normalised floats into SAX chars
+stringifyBuffer(Buffer bufferIn)
+{
+    char* outputString = (char*) malloc((bufferIn.length + 1) * sizeof(char));
+    
+    int i;
+    for(i = 0; i < bufferIn.length; i++)
+    {
+        outputString[i] = valueToSAXChar(bufferIn.items[i]);
+    }
+    
+    outputString[bufferIn.length] = '\0'; // add null terminator
+    return outputString;
+}
+
+#endif