NEWS.md

spsurvey 5.5.1

Bug Fixes

• Fixed a bug in revisit_dsgn() that prevented proper printing of panels when there were multiple panels.
• Fixed a bug that prevented grts() and irs() from working properly with empty LINESTRING or POLYGON geometries.
• Fixed a bug that prevented grts() and irs() from returning coordinates when the the geometry column of sframe was not "geometry" and legacy_sites was specified (#40).

spsurvey 5.5.0

Minor Updates

• n_over is now recycled if the design is stratified and n_over is a length-one numeric vector.
• Added an adjwgtNR() function to perform non-response weight adjustments.
• Warning and error messages from grts(), irs(), and *_analysis() functions now print using message() instead of cat(). This change makes the resulting output more consistent with standard practice and easier to suppress when desired (#36).
• Changed default behavior in attrisk_analysis(), diffrisk_analysis(), and relrisk_analysis() regarding the handling of response_levels and stressor_levels. Previously, if response_levels and stressor_levels were specified, their elements required names. Now, if response_levels is specified and its names are NULL, then its names are set to vars_response, and if stressor_levels is specified and its names are NULL, then its names are set to vars_stressor (#33).

Bug Fixes

• Fixed a bug that caused an error in grts() and irs() occurred when at least one variable name in sframe was named "siteID", "siteuse", "replsite", "lon_WGS84", "lat_WGS84", "stratum", "wgt", "ip", "caty", "aux", xcoord, ycoord, or idpts and the name of the geometry column in sframe was not named "geometry" (#32).

spsurvey 5.4.1

Minor Updates

• Updated citation information to Dumelle et al. (2023) doi:10.18637/jss.v105.i03.

spsurvey 5.4.0

Minor Updates

• Added an sp_frame() function to create sp_frame objects for use with plot() and summary() for sampling frames and analysis data.
  • sp_frame objects have class sp_frame.
• Added an sp_unframe() function to transform sp_frame objects back into their original object type.
• Objects output from grts() and irs() are now called sp_design objects instead of spdesign objects.
  • sp_design objects have class sp_design.
• summary() now works with sp_frame objects and sp_design objects.
  • sp_summary() yields equivalent summaries and is currently maintained for backwards compatibility (i.e., sp_summary() has not changed).
• summary functions now also summarize sf object geometries if the name of the geometry list-column is provided in the summary formula.
• plot() now works with sp_frame objects and sp_design objects.
  • sp_plot() yields equivalent plots and is currently maintained for backwards compatibility (i.e., sp_plot() has not changed).
• plot() now works with sp_CDF objects that are output from the CDF element of cont_analysis().
  • cdf_plot() yields equivalent plots and is currently maintained for backwards compatibility (i.e., cdf_plot() has not changed).
• Updated print functions for summaries obtained via summary() or sp_summary() so that they are clearer and easier to read.
• Added a print function for sp_design objects. Now, a summary of site counts by site type (Legacy, Base, Over Near) crossed by strata or unequal probability levels or both is provided.
• Added stratum_var, caty_var, and aux_var elements to the design list in sp_design objects.
• Added legacy_stratum_var, legacy_caty_var, and legacy_aux_var elements to the design list in sp_design objects when legacy sites are used.
• Added a "total" option to test in change_analysis().
• Minor documentation updates.
• Minor vignette updates.
• Minor stability updates.

Bug fixes

• Fixed a bug that prevented proper printing of the Indicator column when using change_analysis() with test = median.
• Fixed a bug that made change_analysis sensitive to the ordering of the levels of variables in var_cat if those variables were factors.
• Fixed a bug in sp_summary() that incorrectly ordered the siteuse variable.
• Fixed a bug in sp_summary() that failed to summarize data frames that did not have an sf_column attribute.
• Fixed a bug in *_analysis() functions when popsize is a list intended for use with survey::calibrate().
• Fixed a bug in *analysis() functions that returned an error while performing percentile estimation when there was no variability in at least one variable in vars for at least one level of one variable in subpops.
• Fixed a bug in grts() that caused an error for some combinations of n_base and n_over.
• Fixed a bug in change_analysis() that returned an error when at least one variable in vars_cat has only one unique value.

spsurvey 5.3.0

Minor updates

• Added a projcrs_check argument to grts() and irs(), which checks whether projected coordinates are required (projcrs_check = TRUE) or not (projcrs_check = FALSE).
• Nearest neighbor replacement sites (specified by n_near) in grts() or irs() are now also generated for each observation in legacy_sites.

Bug fixes

• Fixed a bug in attrisk_analysis(), diffrisk_analysis(), and relrisk_analysis() that sometimes caused names in response_levels to not be found.
• Fixed a bug in grts() and irs() that returned an error when the name of the geometry column in sframe and legacy_sites differed. Now when this occurs, the geometry column in legacy_sites is renamed to have the same name as the geometry column in sframe.
• Fixed a bug in grts() and irs() that prevented legacy_stratum_var, legacy_caty_var and legacy_aux_var from performing properly.
• Fixed a bug in grts() and irs() that returned an error when at least one stratum in legacy_sites had zero observations.
• Fixed a bug in grts() and irs() that prevented warnprnt() from performing properly.
• Removed the warning in grts() and irs() that indicated when m or z values in sframe or legacy_sites were dropped. Now, the dropping of m or z values is explained in the documentation.
• Removed a warning in grts() and irs() that indicated when row names were set if legacy_sites was a tibble. Now, legacy_sites is coerced to a base R data frame (i.e., not a tibble) before setting row names.
• Added an error in grts() and irs() when legacy_stratum_var (and legacy_caty_var and legacy_aux_var) are NULL but the name of stratum_var in sframe is not contained in legacy_sites.
• Added an error in grts() and irs() that checks whether sframe and legacy_sites have the same crs.
• Updated documentation for pt_density in grts() and irs() to indicate that pt_density must be a positive integer.
• Fixed a bug in sp_summary() that returned an error when formula = ~ . and the geometry column was not named "geometry". Now, sp_summary() works with formula = ~ . regardless of the name of the geometry column.
• Fixed a bug in grts() and irs() that affected minimum distance performance when legacy sites were used.

spsurvey 5.2.0

Minor updates

• Made it easier in grts() and irs() to specify reverse hierarchically ordered replacement sites with unequal selection probabilities by requiring n_over be an integer and removing caty_n_over.
• Added an argument to grts() and irs() called sep, which acts as a separator between the character string created by DesignID and SiteBegin in the sites output.
• The pt_density argument in grts() and irs() now reflects the site multiplier (instead of the per-unit density of sframe) that generates the approximation to sframe when sampling from LINESTRING, MULTILINESTRING, POLYGON, or MULTIPOLYGON sf objects.

Bug fixes

• Fixed a bug in grts() and irs() that prevented use when the geometry column of sframe was not named "geometry".
• Fixed a bug in grts() and irs() that sometimes caused unequal selection probabilities to be misrepresented when reverse hierarchically ordered replacement sites were desired.
• Fixed a bug in grts() and irs() that sometimes prevented the dropping of an sf object's z or m dimension.
• Fixed a bug in grts() and irs() that sometimes incorrectly copied stratum values as caty values in the sites output.
• Fixed a bug in grts() and irs() that prevented sampling from LINESTRING, MULTILINESTRING, POLYGON, or MULTIPOLYGON sf objects when pt_density was excessively large.

spsurvey 5.1.0

Minor updates

• Added a Total option to the statistics argument in cont_analysis().
• Added localmean_weight(), localmean_var(), and localmean_cov() functions to compute the local neighborhood variance estimator outside of the *_analysis() functions.
• Added an option to provide a bounding box vector to the fix_bbox argument in sp_plot().
• Added an error message to grts() and irs() that stops the function when geographic coordinates are used.
• Added an error message to grts() and irs() that stops the function when too many expected samples are specified for at least one level of an unequal probability variable.
• Added a caty_n_over argument to grts() and irs() that makes it easier to specify reverse hierarchically ordered replacement sites for unequal probability sampling designs.
• Added vector argument support for the n_over and n_near arguments in grts() and irs() (list arguments were already supported).
• Added a default value for siteID in attrisk_analysis(), cat_analysis(), cont_analysis(), diffrisk_analysis(), and relrisk_analysis() that assumes each row in dframe represents a unique site.

Bug fixes

• Fixed a bug in irs() that made the algorithm sensitive to the ordering of sframe.
• Fixed a bug in percentile estimation from cont_analysis() that incorrectly copied estimate values.
• Fixed a bug in grts() and irs() that prevented sampling from sframe when the geometry type was LINESTRING, MULTILINESTRING, POLYGON, or MULTIPOLYGON and the number of desired samples exceeded the number of rows.

spsurvey 5.0.1

Bug fix

• Addressed Solaris performance problems.

spsurvey 5.0.0

Major Updates

• Syntax for the grts() (Generalized Random Tessellation Stratified) and irs() (Independent Random Sampling) functions has been significantly simplified. These functions now require the sampling frame is an sf object.

• The grts() and irs() functions now accommodate legacy (or historical) sites, a minimum distance between sites, and two approaches for selecting replacement sites (reverse hierarchical ordering and nearest neighbor).

• Syntax for the analysis functions (*_analysis()) has been significantly simplified.

• Risk difference analysis is now available using the diffrisk_analysis() function.

• Trend analysis is now available using the trend_analysis() function.

• The sp_summary() function is now available to summarize sampling frames, design sites, and analysis data.

• The sp_plot() function is now available to visualize sampling frames, design sites, and analysis data.

Minor Updates

• Several functions have undergone minor changes to syntax and scope.

Breaking Changes

• Several functions have changed (both inputs and outputs) and functions in version 5.0.0 are not always backwards compatible with functions from previous versions. Though we recommend users upgrade existing code to work with the current version's simpler implementations, backwards compatibility can be achieved by downloading previous versions of spsurvey.

spsurvey 4.1.4

Bug fix

• This is a bug-fix release to specifically address issue:
• A new check in R-devel (part of --as-cran) looks for return without (): this is reported on the CRAN results pages for fedora-clang and fedora-gcc.

spsurvey 4.1.3

Bug fix

• Fixed code so that sp design objects inherit CRS of input files and shapefiles written out also have inherited projection from input file. (#2)

• Variable sframe$len was used in grts function and never defined. Now uses length_mdm that is calculated earlier. (#6)

spsurvey 4.1.2

Bug fix

• Update test data and Description file to handle changes in sf and changes to crs described here

spsurvey 4.1.1

Bug fix

• Fix to localmean.weight function to correct when class for matrix objects was causing an indicator variable to have length two rather than length one, which caused an error in a while statement.

spsurvey 4.1.0

Breaking changes

• Functions that create survey designs were modified to replace use of shapefiles to provide the survey frame with use of simple features sf objects to provide the survey frame. To accommodate this change, argument src.frame for functions grts and irs now will accept the choice sf.object to indicate that an sf object will be used as the source of the survey frame. In addition, a new argument named sf.object was added to functions grts and irs to allow input of an sf object as the survey frame. Also, note that arguments id, maxtry, and prjfilename for functions grts and irs have been depricated since they are no longer needed. Finally, the three rda files in the data directory that contain survey frame objects (NE_lakes, Luck_Ash_streams, and UT_ecoregions) were revised to contain sf objects rather than objects belonging to classes that are defined in the sp package.

• The package no longer contains any functions written in C. The C functions were either no longer required due to the transition to use of sf objects to contain the survey frame or were replaced with functions written in R. The new R functions are: cellWeight, constructAddr, insideAreaGridCell, insideLinearGridCell, make_grid, numLevels, pickFiniteSamplePoints, pickGridCells, pickSamplePoints, ranho, and selectFeatureID.

Bug fixes

• The new R code function named numLevels that determines the number of hierarchical levels for a generalized random-tessellation stratified (GRTS) survey design now includes code to ensure that the maximum number of levels (which is currently 11) is not bypassed when creating a survey design.

Modified function

• Modified function input.check to check for missing values among the x-coordinates and y-coordinates for location.

spsurvey 4.0.0

New features

• Necessary changes were enacted so that the package can be built within RStudio, e.g., roxygen comments were added to R source files.

• Created functions that create panel designs and that compute and plot power for panel designs given a linear trend. Function revisit_dsgn creates a panel revisit design. Function revisit_bibd creates a balanced incomplete block panel revisit design. Function revisit_rand creates a revisit design with random assignment to panels and time periods. Function panel_summary summarizes characteristics of a revisit panel design. Function power.dsgn calculates power for multiple panel designs. Function cov.panel.dsgn creates the covariance matrix for a panel design. Function plot.powerpaneldesign plots power curves for panel designs.

Bug fixes

• Modified C function readDbfFile to avoid PROTECT errors.

spsurvey 3.4.0

Bug fixes

• Modified C functions insideAreaGridCell, insideLinearGridCell, linSample, linSampleIRS, numLevels, pickAreaSamplePoints, pickLinearSamplePoints, and pointInPolygonFile to avoid PROTECT errors.

• Modified function change.analysis to assign the support_2 variable from the design_2 data frame rather than from the design_1 data frame.

• Modified function change.analysis to use a revised procedure for ensuring that each repeated visit site is present in both surveys for subpopulation estimation.

• Modified C functions writeShapeFilePoint and writeShapeFilePolygon to correct memory access errors.

• Modified C function readDbfFile to ensure that missing values (NA) are handled correctly.

spsurvey 3.3.0

New features

• Inserted a SystemRequirements field in the DESCRIPTION file and modified functions grts, grtsarea, grtslin, grtspts, irs, irsarea, irslin, read.dbf, and read.shape to prevent the functions from being executed on big-endian processors.

Bug fixes

• Removed the C header file named order.h and replaced C functions readBigEndian and readLittleEndian with the version of those functions from spsurvey version 3.1.

spsurvey 3.2.0

New features

• Created a vignette for change estimation.

• Modified functions change.analysis and change.est to include estimation for difference in median values for change estimation using continuous variables.

• Created a function named examine that examines variables in a data frame by printing either a table or the results of a call to the describe function in the Hmisc package.

Bug fixes

• Modified function sp2shape to accommodate objects of class SpatialDesign created by either the grts or irs functions.

• Added a C header file named order.h that determines whether the CPU employs big-endian or little-endian byte order. Also, modified C functions readBigEndian and readLittleEndian to use constants created by the header file to ensure that computer words are read in the correct byte order.

• Modified function input.check to ensure that use of numeric variables for arguments stratum and cluster are handled correctly when finite or continuous population correction factors are utilized.

• Modified function cdf.test to ensure upper bounds that define classes for the CDFs are unique. Also, modified functions cont.cdftest and cdf.test to reduce the minimum number of upper bounds that define classes for the CDFs from three to two.

• Modified functions sp2shape and read.dbf to ensure that missing values are handled without error for character vectors.

• Modified functions grts and irs to ensure that a dataframe object is assigned to argument att.frame when argument src.frame is assigned value att.frame.

• Modified function change.analysis to ensure that each repeated visit site is present in both surveys for subpopulation estimation.

• Modified function read.sas to use "C:/Program Files/SASHome/SASFoundation/9.4/sas.exe" as the default value for argument sascmd.

spsurvey 3.1.0

New features

• Modified vignettes to use data sets from the data directory for the package.

Bug fixes

• Modified C functions to ensure that variables passed to function malloc are of type unsigned integer.

spsurvey 3.0.0

New features

• Created a class named SpatialDesign that contains class SpatialPointsDataFrame, which is defined in package sp. The class is used for the output objects created by functions grts and irs. Objects of class SpatialDesign include the survey design list as a slot rather than as an attribute, which was used previously.

• Created S3 and S4 methods for generic functions plot and summary for objects of class SpatialDesign.

Bug fixes

• Modified C functions to change the type declaration for variable shpFileName from const char * to char * restrict.

• Modified C functions writeDbfFile, writeShapeFilePoint, and writeShapeFilePolygon to change the return type from void to SEXP NULL, i.e., R_NilValue.

• Modified function input.check to remove missing values from final adjusted weights prior to checking that all values are positive.

• Modified functions grtspts, grtslin, and grtsarea to ensure that argument nlev (number of hierarchical levels) for C function constructAddr was stored as type integer.

spsurvey 2.7.0

New features

• Added a cex.main argument to the cont.cdfplot and cdf.plot functions.

Bug fixes

• Modified function warnprnt to use correct variable names in the output data frame so that partial matching warnings for the names are not generated.

spsurvey 2.6.0

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.

spsurvey 2.5.0

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.

spsurvey 2.4.0

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.

spsurvey 2.3.0

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 design.

• Added a function named ash1.wgt that computes the average shifted histogram (ASH) for weighted data.

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, code{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.

• 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.

spsurvey 2.2.0

New features

• In order to reduce package size, removed demonstration (demo) 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 functions grts and irs 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.

spsurvey 2.1.0

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.

spsurvey 2.0.0

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.

spsurvey 1.7.0

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.

spsurvey 1.6.0

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".

spsurvey 1.5.0

Bug fixes

• Modified C functions getRecordShapeSizes and lintFcn to accommodate Polyline shapefiles that have multiple parts.

spsurvey 1.4.0

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, grtspts, 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.

spsurvey 1.3.0

New features

• Added an example polygons dataset to the data directory.

• Incorporated the CHANGES, README, and UserGuide files into the help page.

spsurvey 1.2.0

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.

spsurvey 1.1.0

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.

spsurvey 1.0.0

New features

• This is the original version of the package.