SnackBot API and time series analysis

snackbot_byday.sas

/* 
   Described in the blog post: 
   The Internet of Snacks: SnackBot data and what it reveals about SAS life
   https://blogs.sas.com/content/sasdummy/snackbot-api-timeseries/
   by Chris Hemedinger
*/
/* Use these ODS statements in SAS for Windows or SAS Enterprise Guide */
ods _all_ close;
filename results "%sysfunc(getoption(WORK))/snackbot.htm";
ods html5 file=results style=Htmlencore gtitle options(svg_mode="inline");

/* Use this one instead for SAS University Edition or SAS Studio */
/*
ods html5 (id=web) style=Htmlencore gtitle options(svg_mode="inline");
*/

%let start = '20MAY2018:0:0:0'dt;

/* format the start/end per the API needs */
%let start_time= %sysfunc(putn(&start.,is8601dt26.));
%let end_time=   %sysfunc(datetime(),is8601dt26.);

/* Call the SnackBot API from snackbot.net */
filename resp temp;
proc http
  method="GET"
  url="http://snackbot.net/snackdata?start_time=&start_time.%str(&)end_time=&end_time.%str(&)utc_offset_minutes=-240"
  out=resp;
run;

/* JSON libname engine to read the result       */
/* Simple record layout, all in the ROOT member */
libname mms json fileref=resp;

/* raw count data at sampled timestamps  */
/* with a few timestamp transformations, */
/* just for exploration                  */
data mmlevels;
  set mms.root;
  drop ordinal_root timestamp;
  /* Convert the TIMESTAMP field to native value -- it's a character */
  datetime = input(timestamp, anydtdtm.);
  date = datepart(datetime);
  time = timepart(datetime);
  dow = date;
  qhour = round(datetime,'0:15:0'T);
  format  datetime datetime20. 
          qhour datetime20.
          date date9.
          time timeampm10.
          dow downame.;
run;

/* Empty data set with 15 minute interval slots    */
/* Regular intervals for the entire "study" period */
data timeslots;
  last = datetime();
  length qhour 8;
  format qhour datetime20;
  drop last i;
  do i = &start. to last by '0:15:00't;
    qhour = i;
    output;
  end;
run;

/* Merge the sample data with the timeslots */
data expand;
  merge mmlevels(keep=pieces qhour) timeslots;
  by qhour;
run;

/* for empty timeslots, carry the sample data   */
/* forward, so we always have a count of pieces */
/* Variation on a LOCF technique                */
data final;
  set expand;
  length day $ 3;
  day=put(datepart(qhour),weekdate3.);
  retain hold;
  if not missing(pieces) then
    hold=pieces;
  else pieces=hold;
  drop hold;
  if not missing(pieces);
run;

/* Decriptive stats broken down by day of week */
title "SnackBot readings per day-of-week";
proc means data=mmlevels mean stddev max min;
 var pieces;
 class dow;
run;

/* Count of readings per hour of the day */ 
title "SnackBot readings per hour";
proc freq data=mmlevels ;
 table time / out=perhour;
 format time hour2.;
run;

ods graphics / imagefmt=svg height=400 width=800;

title "SnackBot readings per hour";
proc sgplot data=perhour des="Readings per hour of day";
 step x=time y=count;
 xaxis min='0:0:0't max='24:0:0't label="Time of day" grid;
 yaxis label="Servings";
run;

title 'Plain M&M pieces on S1 tracked by SnackBot';
ods graphics / imagefmt=svg height=300 width=1600;

proc sgplot data=final des='M&M pieces tracked by SnackBot';

  /* plot the data as a series */ 
  series x=qhour y=pieces / lineattrs=(color=navy thickness=3px);

  /* Yes, these are the "official" M&M colors               */
  /* Will be applied in data-order, so works best when data */
  /* begins on a Sunday                                     */
  styleattrs datacolors=(red orange yellow green blue CX593B18 red);
  /* block areas to indicate days-of-week                   */
  block x=qhour block=day / transparency=0.65
    valueattrs=(weight=bold size=10pt color=navy);

  xaxis minor display=(nolabel);
  yaxis display=(nolabel) grid max=1600 minor;
run;

ods html5 close;