vignettes/addition_parameters.Rmd
addition_parameters.RmdEvery functions carries three boolean parameters that allow better
utilization of these functions in R pipelines and reports. These are
.complete_output, .quiet and
.messages. The default setting of these variables is such
that the calls are as silent as possible and create pretty much no
output in R console at all.
To avoid the situation where you have a lot of calls to
qgis functions and you want them all to behave in the same
non-standard way (i.e. you would prefer that the functions should be
more talkative) you can set the parameters as R options. The options
are: options(qgis.quiet = TRUE),
options(qgis.messages = FALSE) and
options(qgis.complete_output = TRUE). The values of these
options are used as inputs for functions if these options exist,
otherwise default values are used.
## Linking to GEOS 3.10.2, GDAL 3.4.1, PROJ 8.2.1; sf_use_s2() is TRUE
nc <- st_read(system.file("shape/nc.shp", package="sf"), quiet = TRUE)Parameter .quiet (default values is TRUE)
is the same as in qgisprocess::qgis_run_algorithm() only in
qgis the functions are silent by default while in
qgisprocess they are talkative.
Default values is TRUE and the output is silent.
buffered <- qgis::qgis_buffer(INPUT = nc,
DISTANCE = 0.5,
END_CAP_STYLE = "Flat",
.quiet = TRUE) %>%
st_as_sf()## Attempting to load the package cache ...
## Standard error message from 'qgis_process':
## QStandardPaths: runtime directory '/tmp' is not owned by UID 1001, but a directory permissions 0777 owned by UID 0 GID 0
##
##
## Success!With value set to FALSE the function tells you about the
parameters and qgis_process call.
buffered <- qgis::qgis_buffer(INPUT = nc,
DISTANCE = 0.5,
END_CAP_STYLE = "Flat",
.quiet = FALSE) %>%
st_as_sf()## JSON input ----
## {
## "inputs": {
## "INPUT": "/tmp/RtmplqXhfm/fileddabb994290/fileddab23bccbee.gpkg",
## "DISTANCE": 0.5,
## "END_CAP_STYLE": 1,
## "JOIN_STYLE": 0,
## "OUTPUT": "/tmp/RtmplqXhfm/fileddabb994290/fileddabc60c4db.gpkg"
## }
## }
##
## Running qgis_process --json --skip-loading-plugins run 'native:buffer' -Parameter .messages (default value is
FALSE) controls if messages produced by
qgisprocess (such as information about parameters not being
set etc.) should be outputed or not.
Default values is FALSE and the output is silent.
buffered <- qgis::qgis_buffer(INPUT = nc,
DISTANCE = 0.5,
END_CAP_STYLE = "Flat",
.messages = FALSE) %>%
st_as_sf()With value set to TRUE the function tells you about
default parameters values that were not set in the call.
buffered <- qgis::qgis_buffer(INPUT = nc,
DISTANCE = 0.5,
END_CAP_STYLE = "Flat",
.messages = TRUE) %>%
st_as_sf()## Argument `SEGMENTS` is unspecified (using QGIS default value).## Using `JOIN_STYLE = "Round"`## Argument `MITER_LIMIT` is unspecified (using QGIS default value).## Argument `DISSOLVE` is unspecified (using QGIS default value).## Argument `SEPARATE_DISJOINT` is unspecified (using QGIS default value).## Using `OUTPUT = qgis_tmp_vector()`## QStandardPaths: runtime directory '/tmp' is not owned by UID 1001, but a directory permissions 0777 owned by UID 0 GID 0## Using non-preferred coordinate operation between EPSG:4267 and EPSG:4326. Using +proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=clrk66 +step +proj=helmert +x=-10 +y=158 +z=187 +step +inv +proj=cart +ellps=WGS84 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg, preferred +proj=pipeline +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=ca_nrc_ntv2_0.tif +step +proj=unitconvert +xy_in=rad +xy_out=deg.