Documentation Example 1 for PROC VARIOGRAM
/****************************************************************/
/* S A S S A M P L E L I B R A R Y */
/* */
/* NAME: VROEX1 */
/* TITLE: Documentation Example 1 for PROC VARIOGRAM */
/* PRODUCT: STAT */
/* SYSTEM: ALL */
/* KEYS: spatial analysis, semivariogram, model fitting */
/* PROCS: VARIOGRAM */
/* DATA: */
/* */
/* SUPPORT: alkolo */
/* REF: PROC VARIOGRAM, EXAMPLE 1 */
/* MISC: */
/****************************************************************/
title 'Semivariogram Model Fitting of Log-Arsenic Concentration';
data logAsData;
input East North logAs @@;
label logAs='log(As) Concentration';
datalines;
193.0 296.6 -0.68153 232.6 479.1 0.96279 268.7 312.5 -1.02908
43.6 4.9 0.65010 152.6 54.9 1.87076 449.1 395.8 0.95932
310.9 493.6 -1.66208 287.8 164.9 -0.01779 330.0 8.0 2.06837
225.7 241.7 0.15899 452.3 83.4 -1.21217 156.5 462.5 -0.89031
11.5 84.4 -0.24496 144.4 335.7 0.11950 149.0 431.8 -0.57251
234.3 123.2 -1.33642 37.8 197.8 -0.27624 183.1 173.9 -2.14558
149.3 426.7 -1.06506 434.4 67.5 -1.04657 439.6 237.0 -0.09074
36.4 175.2 -1.21211 370.6 244.0 3.28091 452.0 96.5 -0.77081
247.0 86.8 0.04720 413.6 373.2 1.78235 253.5 291.7 0.56132
129.7 111.9 1.34000 352.7 42.1 0.23621 279.3 82.7 2.12350
382.6 290.7 0.86756 188.2 222.8 -1.23308 382.8 154.5 -0.94094
304.4 309.2 -1.95158 337.5 387.2 -1.31294 490.7 189.8 0.40206
159.0 100.1 -0.22272 245.5 329.2 -0.26082 372.1 379.5 -1.89078
417.8 84.1 -1.25176 173.9 407.6 -0.24240 121.5 107.7 1.54509
453.5 313.6 0.65895 143.5 346.7 -0.87196 157.4 125.5 -1.96165
371.8 353.2 -0.59464 358.9 338.2 -1.07133 8.6 437.8 1.44203
395.9 394.2 -0.24144 149.5 58.9 1.17459 453.5 420.6 -0.63951
182.3 85.0 1.00005 21.0 290.1 0.31016 11.1 352.2 -0.88418
131.2 238.4 -0.57184 104.9 6.3 1.12054 247.3 256.0 0.14019
428.4 383.7 0.92448 327.8 481.1 -2.72543 199.2 92.8 -0.05717
453.9 230.1 0.16571 205.0 250.6 0.07581 459.5 271.6 0.93700
229.5 262.8 1.83590 370.4 228.6 2.96611 330.2 281.9 1.79723
354.8 388.3 -3.18262 406.2 222.7 2.41594 254.4 393.1 2.03221
96.7 85.2 -0.47156 407.2 256.8 0.66747 498.5 273.8 1.03041
417.2 471.4 -1.42766 368.8 424.3 -0.70506 303.0 59.1 1.43070
403.1 264.1 1.64554 21.2 360.8 0.67094 148.2 78.1 2.15323
305.5 310.7 -1.47985 228.5 180.3 -0.68386 161.1 143.3 1.07901
70.5 155.1 0.54652 363.1 282.6 -0.43051 86.0 472.5 -1.18855
175.9 105.3 -2.08112 96.8 426.3 1.56592 475.1 453.1 -1.53776
125.7 485.4 1.40054 277.9 201.6 -0.54565 406.2 125.0 -1.38657
60.0 275.5 -0.59966 431.3 494.6 -0.36860 399.9 399.0 -0.77265
28.8 311.1 0.91693 166.1 348.2 -0.49056 266.6 83.5 0.67277
54.7 356.3 0.49596 433.5 460.3 -1.61309 201.7 167.6 -1.40678
158.1 203.6 -1.32499 67.6 230.4 1.14672 81.9 250.0 0.63378
372.0 50.7 0.72445 26.4 264.6 1.00862 300.1 91.7 -0.74089
303.0 447.4 1.74589 108.4 386.2 1.12847 55.6 191.7 0.95175
36.3 273.2 1.78880 94.5 298.3 -2.43320 366.1 187.3 -0.80526
130.7 389.2 -0.31513 37.2 324.2 0.24489 295.5 211.8 0.41899
58.6 206.2 0.18495 346.3 142.8 -0.92038 484.2 215.9 0.08012
451.4 415.7 0.02773 58.9 86.5 0.17652 212.6 363.9 0.17215
378.7 407.6 0.51516 265.9 305.0 -0.30718 123.2 314.8 -0.90591
26.9 471.7 1.70285 16.5 7.1 0.51736 255.1 472.6 2.02381
111.5 148.4 -0.09658 440.4 375.0 1.23285 406.4 19.5 1.01181
321.2 65.8 -0.02095 466.4 357.1 -0.49272 2.0 484.6 0.50994
200.9 205.1 0.43543 30.3 337.0 1.60882 297.0 12.7 1.79824
158.2 450.7 0.05295 122.8 105.3 1.53936 417.8 329.7 -2.08124
;
ods graphics on;
/* Exploratory analysis of log-Arsenic data --------------------*/
proc variogram data=logAsData plots=pairs(mid);
compute novariogram nhc=50;
coord xc=East yc=North;
var logAs;
run;
proc variogram data=logAsData plots(only)=semivar;
compute lagd=5 maxlag=40;
coord xc=East yc=North;
var logAs;
run;
/* Fitting and Selection of a Semivariance Model ---------------*/
proc variogram data=logAsData plots(only)=fit;
store out=SemivAsStore / label='LogAs Concentration Models';
compute lagd=5 maxlag=40;
coord xc=East yc=North;
model form=auto(mlist=(exp,gau,mat) nest=1 to 2);
var logAs;
run;
ods graphics off;
