options nodate nonumber ps=500 ls=80;

data one;
infile 'H:\public_html\data\atltime.dat';
input date $ 1-10 fltnum tailnum $ city $ time distance;
run;

proc sort;
by city time;
run;

data two;
set one;
by city time;
retain citymin citymax citysum citysum2 cityn;
if first.city then do;
citymin=time;
citysum=0;
citysum2=0;
cityn=0;
end;
citysum=citysum+time;
citysum2=citysum2+(time*time);
cityn=cityn+1;
if last.city then do;
citymax=time;
citymean=citysum/cityn;
citystd=sqrt((citysum2-(cityn*citymean*citymean))/(cityn-1));
output;
end;
run;

data three;
set two;
keep city citymin citymax citymean citystd cityn distance;
run;

symbol1 c=black v=:;

proc gplot;
plot citymean*distance=1 / frame;
run;

quit;
proc gplot;
plot citymean*citystd=1 / frame;
run;

quit;

proc gplot;
plot citystd*distance=1 / frame;
run;

quit;

/*


proc print;
run;
quit;