NROWS — Vector of length NSTRAT in which ∣NROWS(I)∣ is the number of items from the I‑th stratum currently input in X and Y. (Input)
Each element of NROWS may be positive, zero, or negative. A negative value for NROWS(I) means delete the ‑NROWS(I) elements of the I‑th stratum in X and Y from the analysis.

X — Vector containing the data for the auxiliary variable in the stratified random sample. (Input)
The observations within any one stratum must appear contiguously in X. The first ∣NROWS(1)∣ elements of X are from the first stratum, and so on.

Y — Vector containing the data for the variable of interest in the stratified random sample. (Input)
The observations within any one stratum must appear contiguously in Y. The first ∣NROWS(1)∣ elements of Y are from the first stratum, and so on. The value of Y(I) corresponds to that of X(I).

NPOPS — Vector of length NSTRAT containing the sizes of the population in the strata. (Input)
The entries in NSTRAT must be ordered in correspondence with the ordering of strata in the other vectors. If the population strata sizes are not known, estimates must be entered in their place.

XMEANS — Vector of length NSTRAT containing, for each stratum, the population mean of the auxiliary variate, provided ITOPT = 0. (Input)
If ITOPT = 1, only XMEANS(1) is defined and it must contain the population mean of the auxiliary variate.

COEFS — Vector of length NSTRAT containing the ratio estimates or the regression coefficients. (Input, if IOPT = 1; Output, if IOPT = 0 or 2 and IDO = 0 or 1; Input/Output, if IOPT = 0 or 2 and IDO = 2 or 3)
If IOPT = 0, COEFS contains ratio estimates. When ITOPT = 0, COEFS contains the estimate of the ratio for each stratum. When ITOPT = 1, only COEFS(1) is defined and contains the combined estimate of the ratio. If IOPT = 1, COEFS contains preassigned regression coefficients. When ITOPT = 0, COEFS contains the preassigned regression coefficient for each stratum. When ITOPT = 1, only COEFS(1) is defined and contains the preassigned regression coefficient common to all strata. If IOPT = 2, COEFS contains estimated regression coefficients. When ITOPT = 0, COEFS contains the estimated regression coefficient for each stratum. When ITOPT = 1, only COEFS(1) is defined and contains the estimated regression coefficient common to all strata.

XBARS — Vector of length NSTRAT containing the strata means for the auxiliary variable. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

XVARS — Vector of length NSTRAT containing the within‑strata variances of the auxiliary variable. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

XCVS — Vector of length NSTRAT containing the within‑strata coefficients of variation for the auxiliary variable. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

YBARS — Vector of length NSTRAT containing the strata means for the variable of interest. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

YVARS — Vector of length NSTRAT containing the within‑strata variances of the variable of interest. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

YCVS — Vector of length NSTRAT containing the within‑strata coefficients of variation for the variable of interest. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

XYCOVS — Vector of length NSTRAT containing the within‑strata covariances of the auxiliary variable and the variable of interest. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

NSAMPS — Vector of length NSTRAT containing the number of nonmissing observations from each stratum. (Output, if IDO = 0 or 1; Input/Output, if IDO = 2 or 3.)

STAT — Vector of length 12 containing the resulting statistics. (Output)
These are:

IDO — Processing option. (Input)
Default: IDO = 0.

NSTRAT — Number of strata into which the population is divided. (Input)
In the vectors of length NSTRAT, the elements are all ordered in the same way. That is, the first stratum is always the first, the second is always the second, and so on.
Default: NSTRAT = size (NROWS,1).

IOPT — Estimation option. (Input)
Default: IOPT = 0.

ITOPT — Estimation technique option. (Input)
Default: ITOPT = 0.

CONPER — Confidence level for two‑sided interval estimate, in percent. (Input)
A CONPER percent confidence interval is computed; hence, CONPER must be greater than or equal to 0.0 and less than 100.0. CONPER is often 90.0, 95.0, or 99.0. For a one‑sided confidence interval with confidence level ONECL, set CONPER = 100.0 ‑ 2.0 * (100.0 ‑ ONECL).
Default: CONPER = 95.0.