how-to-use-MapR

This vignette provides an overview on how to use MapR. MapR is an App to display temporal and temperature graphical files for Isomemo.

Introduction

To work with MapR, a zip file is needed, which can be uploaded after starting the app. It is also possible to select an online zip file that contains example data. The zip file must contain both the images to be displayed (stored in a folder called data) and a json file that specifies which images are displayed depending on the users selection.

The json file can be an image list (image_list.json) that contains group-, variable- and measure names and the image belonging to each combination of these three. Also for each image, the path where the image can be found in the data folder, must be included.

Alternatively, the json file can be a questionnaire (questionnaire.json). The file must contain questions that are displayed to the user. Furthermore the file must contain the images to be displayed with the information which answer is needed to display a specific image. Also the path where the image can be found in the data folder, must be included again.

Both the image_list.json file or the questionnaire.json must have the same structure as provided in the example zip files.

Some fields need more attention because only specific values are supported by the app:

Within both json files the field file_type must be “png” or “nc”.

Within questionnaire.json

• the field Type belonging to Questions can be either “multiple choice” or “numeric”.
  • If “multiple choice” is selected, the field Answers must contain a list of possible answers (see example files).
  • If “numeric” is selected, the field Answers should be empty. Additionally, one can specify a Fill_Value which is prefilled into the input field. If Fill_Value is an empty string (""), the input field is empty.
• the field Type belonging to Plots can be any mathematical operator (e.g. >, <=, ==, !=, >=, <).

Usage

To start the app one can use the online version or run the following command locally:

library(MapR)
startApplication()

After starting the app a zip file must be uploaded by clicking on the Import ZIP file button. Depending on the concent of the zip file (image_list.json or questionnaire.json), the app will display different inputs that can be filled out by the user. Finally, by clicking on the button Display plot, the image can be displayed.