This extended practical session aims the implementation of some basic DataSHIELD functions and the interpretation of the results, this is possible to do independently having completed the DataSHIELD user tutorial.
# If they haven't been loaded yet, load all the DataSHIELD libraries. library(opal) library(dsBaseClient) library(dsStatsClient) library(dsGraphicsClient) library(dsModellingClient) # build a new dataframe by login to the table "DASIM" which is included in three cloud based Opals server <- c("study1", "study2", "study3") url <- c("http://XXXXXX:8080") table <- c("DASIM.DASIM1", "DASIM.DASIM2", "DASIM.DASIM3") logindata <- data.frame(server,url,user="administrator",password="datashield_test&",table) # login and assign the whole dataset opals <- datashield.login(logins=logindata,assign=TRUE) |
Use functions provided in DataSHIELD packages to solve the following problems:
Calculate the mean and the variance of the continuous variable BMI of obese males.
Check the levels for the variables PM_BMI_CATEGORICAL and GENDER using ds.levels(). BMI is categorised in three levels: 1=normal, 2=overweight, 3=obese and gender is categorised in two levels: 0=male, 1=female. |
When you complete the questions, check your answers and script. |