These functions provide procedures for selecting sites for spatial
surveys using spatially balanced algorithms applied to discrete points,
linear networks, or polygons. The probability survey designs available
include independent random samples, stratified random samples, and unequal
probability random samples (categorical or probability proportional to
size). Design-based estimation based on the results from surveys is
available for estimating totals, means, quantiles, CDFs, and linear models.
The analyses rely on package survey for most results. Variance estimation
options include a local neighborhood variance estimator that is appropriate
for spatially-balanced survey designs. A reference for the survey design
portion of the package is: D. L. Stevens, Jr. and A. R. Olsen (2004),
"Spatially-balanced sampling of natural resources.", Journal of the American
Statistical Association 99(465): 262-278,

NEWS R Documentation

spsurvey News

CHANGES IN spsurvey VERSION 2.6 (Released 2013-09-20)

NEW FEATURES

```
� Created a data directory that contain rda versions of the
data files used by vignettes.
```

BUG FIXES

```
� Modified function 'change.analysis' to allow analysis of
surveys with no repeat visit sites.
� Modified function 'change.est' to ensure that levels for a
categorical response variable are listed in the desired
order rather than sorted order.
� Modified function 'localmean.weight' to allow recovery from
an error in the singular value decomposition function
(La.svd) that is called by the generalized inverse function
(ginv) in the MASS package. Also, created a support
function named 'localmean.weight2'.
```

CHANGES IN spsurvey VERSION 2.5 (Released 2012-10-10)

NEW FEATURES

```
� Modified function 'grtspts' and C function 'numLevels' to
calculate the sampling grid random shift values only once
rather than each time the number of hierarchical levels is
incremented.
```

BUG FIXES

```
� Modified functions 'attrisk.analysis', 'cat.analysis',
'change.analysis', 'cont.analysis', and 'relrisk.analysis'
to replace NA values with FALSE in the indicator variables
for subpopulations.
� Modified function 'spbalance' to include all grid cells with
nonzero extent for the frame when calculating the Pielou
evenness measure for a rectangular grid.
� Modified function 'localmean.weight' to ensure that the
initial set of weights are inversely proportional to
distance.
� Modified functions 'cont.cdftest' and 'cdf.test' to ensure
that the number of classes into which the CDFs will be
divided (binned) is at least three.
� Modified function 'dframe.check' to ensure proper handling of
repeated site ID values in the sites data frame.
```

CHANGES IN spsurvey VERSION 2.4 (Released 2012-05-23)

NEW FEATURES

```
� Created a vignette that presents deconvolution of a
cumulative distribution function (CDF) generated by a GRTS
survey design.
� Created a function named 'spbalance' that calculates spatial
balance metrics for a survey design.
� Created functions named 'sbcframe' and 'sbcsamp' that
calculate spatial balance grid cell extent and proportions
for a sample frame and for a survey design, respectively.
� Modified function 'change.est' to include calculation of
resource size change estimates for categorical variables.
� Created a function named 'changevar.size' to calculate
covariance or correlation estimates of the estimated change
in class resource size estimates between two probability
surveys
```

BUG FIXES

```
� Modified function 'change.est' to correct errors in the
output values for categorical variables from survey designs
that lack repeat visit sites.
� Modified the following functions to assign consecutive
numbers to the row names for the output data frame(s):
attrisk.analysis, cat.analysis, change.analysis,
cont.analysis, cont.cdftest, and relrisk.analysis.
```

CHANGES IN spsurvey VERSION 2.3 (Released 2012-02-03)

NEW FEATURES

```
� Created a function named 'change.analysis' that conducts
change analysis for a collection of response variables
(categorical and continuous) generated by two probability
surveys.
� Created functions named 'change.est', 'changevar.prop', and
'changevar.mean' to calculate estimates of change and its
associated variance.
� Created a vignette that presents cumulative distribution
function (CDF) analysis of a GRTS survey designs.
� Added a function named ash1.wgt that computes the average
shifted histogram (ASH) for weighted data.
� Created an .onAttach function that prints a message when the
spsurvey package is attached. Removed the .onLoad function,
which prior versions used to to print a startup message.
```

BUG FIXES

```
� Modified function 'grtspts' to correct an error that occurs
when argument 'src.frame' equals "att.frame" and the number
of hierarchical levels equals eleven.
� Modified C functions 'printAddrList', 'printColCharList',
and 'printDbf' to replace calls to the printf function with
calls to the Rprintf function.
� Modified C function 'pickAreaSamplePoints' to correct an
error that occurs when selecting sample points for PolygonZ
and PolygonM type shapefiles.
```

CHANGES IN spsurvey VERSION 2.2 (Released 2011-05-16)

NEW FEATURES

```
� In order to reduce package size, removed demonstration R
scripts and the associated data directory.
� Created vignettes that present analyses of GRTS survey
designs for finite, linear, and areal resources.
� Created a function named 'attrisk.analysis' that conducts
attributable risk analysis for a collection of response
variables generated by a probability survey.
� Created functions named 'attrisk.est' and 'attrisk.var' to
calculate estimates of attributable risk and its associated
variance.
� Modified function 'relrisk.est' to change the way the
relative risk estimate is calculated for a stratified
sample.
� Modified functions 'cat.analysis', 'cont.analysis',
'cont.cdftest', 'relrisk.analysis', 'category.est',
'cdf.est', 'cdf.decon', 'total.est', 'cdf.test',
'relrisk.est', 'catvar.prop', 'catvar.size', 'cdfvar.prop',
'cdfvar.total', 'cdfvar.size.prop', 'cdfvar.size.total',
'dcdfvar.prop', 'dcdfvar.total', 'dcdfvar.size.prop',
'dcdfvar.size.total', 'total.var', 'cdfvar.test', and
'relrisk.var' to allow variance estimates to be calculated
when a two stage sample has stage one sampling units that
contain a single stage two sampling unit. Variance for
those stage one sampling units is calculated using the mean
of the variance estimates for stage one sampling units that
contain two or more stage two sampling units.
� Modified function 'grtslin' to improve efficiency of sample
point selection. Created a C function named
'insideLinearGridCell' that, for each grid cell selected to
receive a sample point, returns the ID value for shapefile
records contained in the cell and the clipped length of the
polyline segments within the cell for each record. Created
a C function named 'pickLinearSamplePoints' that selects
sample points.
� Modified function 'grtsarea' to improve efficiency of sample
point selection. Created a C function named
'insideAreaGridCell' that, for each grid cell selected to
receive a sample point, returns the ID value for shapefile
records contained in the cell and the clipped area of the
polygon within the cell for each record. Created a C
function named 'pickAreaSamplePoints' that selects sample
points.
```

BUG FIXES

```
� Modified function 'input.check' to include determination of
whether a valid value was provided for argument 'vartype'.
� Modified function 'grts' so that correct survey design
weights are created for linear and areal designs when the
type of random selection is "continuous".
� Modified functions 'grtspts', 'grtslin', and 'grtsarea' to
execute without error for a stratum sample size of one.
� Modified function 'dframe.check' to terminate execution when
missing values are encountered in the logical variable of
the sites data frame.
```

CHANGES IN spsurvey VERSION 2.1 (Released 2009-10-29)

NEW FEATURES

```
� Created vignettes that present examples of GRTS survey
designs for finite, linear, and areal resources.
� Created a function named 'geodalbers' that projects latitude
and longitude (spheroid) models of the globe to Albers
projection in the plane.
� Modified function 'dsgnsum' to produce summary tables for
the actual set of design variables that are present rather
than a standard set of design variables.
� Modified function 'dframe.check' to terminate execution when
missing site ID values or repeated site ID values are
encountered in the 'sites', 'design', 'subpop', 'data.cat',
'data.cont', or 'data.rr' data frames. Note that
'dframe.check' is called by functions 'cat.analysis',
'cont.analysis', 'cont.cdftest', and 'relrisk.analysis'.
```

BUG FIXES

```
� Modified function 'cont.cdftest' to correct an error caused
by improper handling of an empty subpopulation.
� Modified function 'relrisk.analysis' to correct an error
resulting from inclusion of more than one response variable
in the 'response.var' argument.
```

CHANGES IN spsurvey VERSION 2.0 (Released 2008-06-16)

NEW FEATURES

```
� Eliminated use of argument 'unitsize' (known sum of
size-weights) by package functions. Restricted argument
'popsize' to provide only the known size of the resource for
use in ratio adjustment of estimators. Created a new
argument named 'pcfsize' to provide resource size for
calculation of finite and continuous population correction
factors for single-stage samples.
� Modified functions 'cat.analysis', 'cont.analysis',
'cont.cdftest', and 'relrisk.analysis' to add logical
variables to their argument lists that specify use of finite
or continuous population correction factors or use of
size-weights in analysis routines.
� Modified functions 'category.est', 'cdf.decon', 'cdf.est',
'cdf.test', 'relrisk.est' and 'total.est' to add logical
variables to their argument lists that specify use of finite
or continuous population correction factors or use of
size-weights.
```

BUG FIXES

```
� Modified function 'irs' to eliminate checking for existence
of x-coordinates and y-coordinates when the type of frame is
"finite" and the frame is included in the 'att.frame' data
frame.
� Modified C functions 'parseFields' and 'readDbfFile' to
ensure that blank values in the shapefile attributes (dbf)
file are converted to R missing values (NA).
� Modified C function 'writeDbfFile' to output blank values
for R missing values (NA) when creating the shapefile
attributes (dbf) file.
� Modified functions 'grts', 'irs', and 'sp2shape' to ensure
that an output shapefile attributes (dbf) file containing
character variables with missing values can be read without
error.
```

CHANGES IN spsurvey VERSION 1.7 (Released 2007-11-09)

NEW FEATURES

```
� Created a function named 'cont.cdftest' that tests for
differences between cumulative distribution functions (CDFs)
for pairs of subpopulations within a population 'Type' for a
collection of response variables generated by a probability
survey. Also, modified function 'cdf.test' so that it is
consistent with functions that are called by high-level
functions 'cat.analysis' and 'cont.analysis'.
� Modified function 'grtspts' so that, when source of the
frame equals "att.frame", the current number of grid levels
for hierarchical randomization and the final number of grid
levels is printed to the console while the function is
executing.
� Created a function named 'relrisk.analysis' that conducts
relative risk analysis for a collection of response
variables generated by a probability survey. Also, renamed
function 'relrisk' to 'relrisk.est' and modified the
function so that it is consistent with functions that are
called by high-level functions 'cat.analysis' and
'cont.analysis'.
� Modified function 'grtspts' and C function 'numLevels' to
terminate the algorithm for determining the number of grid
levels for hierarchical randomization when the maximum value
of total inclusion probability for the grid cells stops
changing as the number of levels increases.
� Created functions named 'cdf.plot' and 'cont.cdfplot' that
create cumulative distribution function (CDF) plots using
the data frame named "CDF" contained in the output object
created by function 'cont.analysis'. Function 'cdf.plot'
creates a single CDF plot, and function 'cont.cdfplot'
creates a set of CDF plots.
� Created a function named 'read.sas' that can read SAS
datasets or a SAS XPORT (transport) file.
```

BUG FIXES

```
� Modified C functions 'intersect', 'linSampleIRS', 'lintFcn',
and 'linSample' to eliminate warning messages that were
generated during package creation.
� Modified function 'grts' so that argument 'do.sample'
provides a value for each stratum.
� Modified C functions 'getRecordShapeSizes', 'readDbfFile',
'parsePoints', 'parsePointsZ', 'parsePointsM',
'parsePolygon', 'parsePolygonZ', and 'parsePolygonM' to
generate error messages and terminate execution when a
shapefile containing a Null record is encountered.
� Modified functions 'irslin' and 'irsarea' in addition to C
function 'getRecordIDs' to ensure that sample points are
selected in random order for linear and areal IRS designs.
� Modified function 'grts' to ensure that, when the type of
random selection is "unequal", an oversample is apportioned
correctly whenever the category sample sizes are
proportional to the oversample size.
```

CHANGES IN spsurvey VERSION 1.6 (Released 2007-01-18)

NEW FEATURES

```
� For C functions that read shapefiles from the current
directory, replaced calls to '_findfirst' and '_findnext'
with code using calls to 'readdir'. These changes were
implemented to facilitate portability of the package.
� Created a C function named 'matchFiles' that determines
whether file names in the current directory have a desired
file extension. This change was implemented to facilitate
portability of the package.
```

BUG FIXES

```
� Modified functions 'grts' and 'irs' to accommodate use of a
factor for the ID variable in the attributes data frame.
� Modified functions 'grts' and 'irs' to ensure that sample
weights are correctly adjusted when an oversample is present
and the type of random selection is "Continuous".
```

CHANGES IN spsurvey VERSION 1.5 (Released 2006-12-06)

NEW FEATURES

```
� None.
```

BUG FIXES

```
� Modified C functions 'getRecordShapeSizes' and 'lintFcn' to
accommodate Polyline shapefiles that have multiple parts.
```

CHANGES IN spsurvey VERSION 1.4 (Released 2006-10-10)

NEW FEATURES

```
� Modified functions 'dsgnsum' and 'sp2shape' to accommodate
the change in representation from 'AttributeList' to
'data.frame' for the data slot of sp package objects
belonging to class 'SpatialPointsDataFrame'.
� Modified functions 'grts' and 'irs' to print a warning
message when the type of frame equals "finite" and a stratum
name in the design list matches only a single value in the
stratum column of the attributes data frame. For this case,
function 'grtspts' or 'irspts' is not called since the
sample will be composed of a single point.
� Modified functions 'grts', 'grts'pts, 'grtslin', and
'grtsarea' to change the maximum value allowed for arguments
startlev (the initial number of hierarchical levels to use
for the GRTS grid) and maxlev (the maximum number of
hierarchical levels to use for the GRTS grid) from 12 to 11.
� Added an example polylines dataset to the data directory.
� Modified functions 'grts' and 'irs' to allow use of an sp
package object as the source of the frame. An argument
named 'sp.object' was added to the argument list for 'grts'
and 'irs'.
� Modified functions 'grts', 'grtspts', 'grtslin', 'grtsarea',
'irs', 'irspts', 'irslin', and 'irsarea' to remove use of
argument 'xy.frame' as an option for source of the frame.
Then modified functions 'grts', 'grtspts', 'irs', and
'irspts' to allow incorporation of frame coordinates into
the attributes data frame when the type of frame equals
"finite". Also, removed argument 'elmsize' from functions
'grts' and 'irs' since the argument no longer was required.
```

BUG FIXES

```
� Modified functions 'grts' and 'irs' to print a warning
message when the type of frame equals "finite" and a stratum
name in the design list matches only a single value in the
stratum column of the attributes data frame. For this case,
function 'grtspts' or 'irspts' is not called since the
sample will be composed of a single point.
� Modified functions 'grts' and 'irs' to ensure that the ID
values for elements of the frame provided in att.frame are
unique.
� Modified functions 'grts' and 'irs' to ensure that valid
values are provided for the 'panel' and 'caty.n' arguments
in the design list.
```

CHANGES IN spsurvey VERSION 1.3 (Released 2006-08-01)

NEW FEATURES

```
� Added an example polygons dataset to the data directory.
� Incorporated the CHANGES, README, and UserGuide files into
the help page.
```

BUG FIXES

```
� None.
```

CHANGES IN spsurvey VERSION 1.2 (Released 2006-06-27)

NEW FEATURES

```
� Created a function named 'sp2shape' and a C function named
'writeShapeFilePolygon' that convert objects created by
package sp to ESRI shapefiles. Also, renamed the C function
'writeShapeFile' to 'writeShapeFilePoint'.
```

BUG FIXES

```
� Modified function 'irsarea' and created a C function 'named
getRecordIDs' to ensure that an IRS sample is selected when
argument 'type.frame' is set to "area" in function 'irs'.
```

CHANGES IN spsurvey VERSION 1.1 (Released 2006-05-31)

NEW FEATURES

```
� Modified the C functions so that the package can accommodate
M-type shapefiles.
```

BUG FIXES

```
� Modified functions 'grts' and 'irs' to ensure that the
levels of 'mdcaty' (the variable in the attributes data
frame that specifies the unequal probability category for
each element in the frame) are equivalent to the names in
'caty.n' (the vector of sample sizes for each category in
'mdcaty', which is required for each element of the design
list for which the selection type is "Unequal").
� Modified functions 'grts' and 'irs' to ensure that the
columns of 'xy.frame' are named "x" and "y" when 'xy.frame'
is provided and 'type.frame' equals "finite".
� Modified functions 'grts' and 'irs' so that the sample
weights are correctly adjusted when an oversample is
requested and the realized sample size is less than the
desired sample size.
```

CHANGES IN spsurvey VERSION 1.0 (Released 2006-05-05)

NEW FEATURES

```
� This is the original version of the package.
```

BUG FIXES

```
� None.
```