Documentation Example 5 for PROC VARIOGRAM
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/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: VROEX5 */
/* TITLE: Documentation Example 5 for PROC VARIOGRAM */
/* PRODUCT: STAT */
/* SYSTEM: ALL */
/* KEYS: spatial analysis, semivariogram, outliers */
/* PROCS: VARIOGRAM */
/* DATA: */
/* */
/* SUPPORT: alkolo */
/* REF: PROC VARIOGRAM, EXAMPLE 5 */
/* MISC: */
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/* Run PROC VARIOGRAM to produce OUTPAIR= data set -------------*/
title 'Square Root Difference Cloud Example';
proc variogram data=sashelp.thick outp=outp noprint;
compute novariogram;
coordinates xc=East yc=North;
var Thick;
run;
/* Obtain data subset to create square root difference cloud ---*/
data sqroot;
set outp;
/*- Include only points +/- 30 degrees of N-S -------*/
where abs(cos) < 0.5;
/*- Unit lag of 7, distance tolerance of 3.5 --------*/
lag_class=int(distance/7 + 0.5000001);
sqr_diff=sqrt(abs(v1-v2));
run;
proc sort data=sqroot;
by lag_class;
run;
/* Summarize results with the MEANS procedure ------------------*/
proc means data=sqroot noprint n mean std;
var sqr_diff;
by lag_class;
output out=msqrt n=n mean=mean std=std;
run;
title2 'Summary of Results';
proc print data=msqrt;
id lag_class;
var n mean std;
run;
/* Create box plot of the square root difference cloud ---------*/
proc sgplot data=sqroot;
xaxis label = "Lag Class";
yaxis label = "Square Root Difference";
title "Box Plot of the Square Root Difference Cloud";
vbox sqr_diff / category=lag_class;
run;