/*------------------------------------------------*/
/* STEP 1: Create Binary BMI Variable (Obesity)   */
/*------------------------------------------------*/

data sasdata_20151;
    set sasdata_20151;

    if _BMI5 = . then bmi_g = .;
    else if _BMI5 >= 3000 then bmi_g = 1;  /* Obese */
    else if 1 < _BMI5 < 3000 then bmi_g = 0; /* Not obese */
run;


/*------------------------------------------------*/
/* STEP 2: Frequency Table                        */
/*------------------------------------------------*/

proc freq data=sasdata_20151;
    tables bmi_g / missing;
run;


/*------------------------------------------------*/
/* STEP 3: Prepare State-Level Data (2015)        */
/*------------------------------------------------*/

/* Calculate obesity prevalence by state */

proc means data=sasdata_20151 noprint;
    class _STATE;
    var bmi_g;
    output out=obesity2015 mean=prev_obesity;
run;

/* Keep valid rows */
data obesity2015;
    set obesity2015;
    where _TYPE_ = 1;
run;


/*------------------------------------------------*/
/* STEP 4: US MAP DATA                            */
/*------------------------------------------------*/

proc gproject data=maps.us out=us_map;
    id state;
run;


/*------------------------------------------------*/
/* STEP 5: Merge Map + Data (2015)                */
/*------------------------------------------------*/

data map_2015;
    merge us_map obesity2015(rename=(_STATE=state));
    by state;
run;


/*------------------------------------------------*/
/* STEP 6: Create Map for 2015                    */
/*------------------------------------------------*/

pattern1 v=s c=lightyellow;
pattern2 v=s c=yellow;
pattern3 v=s c=orange;
pattern4 v=s c=red;

proc gmap data=map_2015 map=us_map;
    id state;
    choro prev_obesity / levels=4;
    title "Age-Adjusted Obesity Prevalence by State (2015)";
run;
quit;


/*------------------------------------------------*/
/* STEP 7: Repeat for 2017 Data                   */
/*------------------------------------------------*/

/* Assume dataset name is sasdata_20171 */

data sasdata_20171;
    set sasdata_20171;

    if _BMI5 = . then bmi_g = .;
    else if _BMI5 >= 3000 then bmi_g = 1;
    else if 1 < _BMI5 < 3000 then bmi_g = 0;
run;

/* Frequency */

proc freq data=sasdata_20171;
    tables bmi_g / missing;
run;

/* State-level prevalence */

proc means data=sasdata_20171 noprint;
    class _STATE;
    var bmi_g;
    output out=obesity2017 mean=prev_obesity;
run;

data obesity2017;
    set obesity2017;
    where _TYPE_ = 1;
run;

/* Merge with map */

data map_2017;
    merge us_map obesity2017(rename=(_STATE=state));
    by state;
run;

/* Map for 2017 */

proc gmap data=map_2017 map=us_map;
    id state;
    choro prev_obesity / levels=4;
    title "Age-Adjusted Obesity Prevalence by State (2017)";
run;
quit;