| ds.glmSummary {dsBaseClient} | R Documentation |
Summarize a glm object on the serverside to create a summary_glm object. Also identify and return components of both the glm object and the summary_glm object that can safely be sent to the clientside without a risk of disclosure
ds.glmSummary(x.name, newobj = NULL, datasources = NULL)
x.name |
a character string providing the name of a glm object on the serverside that has previously been created e.g. using ds.glmSLMA |
newobj |
a character string specifying the name of the object to which the summary_glm object representing the output of summary(glm object) in each study is to be written. If no <newobj> argument is specified, the output object on the serverside defaults to "summary_glm.newobj". |
datasources |
specifies the particular 'connection object(s)' to use. e.g. if you have several data sets in the sources you are working with called opals.a, opals.w2, and connection.xyz, you can choose which of these to work with. The call 'datashield.connections_find()' lists all of the different datasets available and if one of these is called 'default.connections' that will be the dataset used by default if no other dataset is specified. If you wish to change the connections you wish to use by default the call datashield.connections_default('opals.a') will set 'default.connections' to be 'opals.a' and so in the absence of specific instructions to the contrary (e.g. by specifiying a particular dataset to be used via the <datasources> argument) all subsequent function calls will be to the datasets held in opals.a. If the <datasources> argument is specified, it should be set without inverted commas: e.g. datasources=opals.a or datasources=default.connections. The <datasources> argument also allows you to apply a function solely to a subset of the studies/sources you are working with. For example, the second source in a set of three, can be specified using a call such as datasources=connection.xyz[2]. On the other hand, if you wish to specify solely the first and third sources, the appropriate call will be datasources=connections.xyz[c(1,3)] |
Clientside function calling a single assign function (glmSummaryDS.as) and a single aggregate function (glmSummaryDS.as). ds.glmSummary summarises a glm object that has already been created on the serverside by fitting ds.glmSLMA which is precisely the same as the glm object created by fitting a glm using the glm function in native R. Similarly the summary_glm object saved to the serverside is precisely equivalent to the object created using summary(glm object) in R. The glm object produced from a standard call to glm in R has 32 components. Amongst these, all of the following thirteen contain information about every records in the data set and so are disclosive. They are all therefore set to NA and so convey no information when returned to the clientside: 1.residuals, 2.fitted.values, 3.effects, 4.R, 5.qr, 6.linear.predictors, 7.weights, 8.prior.weights, 9.y, 10.model, 11. na.action, 12.x, 13. offset. In addition the list element "data" which identifies a data.frame that was identified as containing all of the variables required for the model is also disclosive because it doesn't list the name of the data.frame but rather prints it out in full. However, a user can benefit from knowing what source of data were used in creating the glm model and so the element "data" that is returned to the clientside simply lists the names of all of the columns in the originating data.frame. Having removed all disclosive elements of the glm object, ds.glmSummary returns the remaining 19 elements to the clientside. The object created from a standard call to summary(glm object) in R contains 18 list elements. Only two of these are disclosive - na.action and deviance.resid and these are therefore set to NA before ds.glmSummary returns the other 16 to the clientside. Further details of the components of the glm object and summary_glm object can be found under help for glm and summary(glm) in native R. In addition, the elements that ARE returned are listed under "return" below.
ds.glmSummary writes a new object to the serverside with name given by the newobj argument or if that argument is missing or null it is called "summary_glm.newobj". In addition, ds.glmSummary returns an object containing two lists to the clientside the two lists are named "glm.obj" and "glm.summary.obj" which contain all of the elements of the original glm object and the summary_glm object on the serverside but with all potentially disclosive components set to NA or masked in another way see "details" above. The elements that are returned with a non-NA value in the glm.obj list object are: "coefficients", "rank", "family", "deviance", "aic", "null.deviance", "iter", "df.residual", "df.null", "converged", "boundary", "call", "formula", "terms", "data", "control", "method", "contrasts", "xlevels". The elements that are returned with a non-NA value in the glm.summary.obj list object are: "call", "terms", "family", "deviance", "aic", "contrasts", "df.residual", "null.deviance", "df.null", "iter", "coefficients", "aliased", "dispersion", "df", "cov.unscaled", "cov.scaled". For further information see help for glm and summary(glm) in native R and for ds.glmSLMA in DataSHIELD.
Paul Burton, for DataSHIELD Development Team 17/07/20