ROC Analysis
Web-based Calculator for ROC Curves
John Eng, M.D. 
Russell H. Morgan Department of Radiology and Radiological Science
Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
To access this page, you may use the link www.jrocfit.org.
 
      
Instructions:  This web page calculates a receiver operating characteristic (ROC) curve from data pasted into the input data field below. To analyze your data, use the following steps to fill out the data form on this page.
  1. Select the data format. (See explanation of data formats.)
  2. Paste or enter your data into the "Input Data" field or click the "Paste Example Data" button. Data may be pasted from programs such as Microsoft Excel or Word.
  3. Enter the number of rating categories. (See explanation of data formats.) This is not needed for the example data or Format 5.
  4. Click the "Run Program" button.
  5. To export the ROC plot to Microsoft Word or Excel, see instructions below.
Computer requirements:  A reasonably up-to-date version of a web browser that supports HTML5 is required. Unlike previous versions of this page, installation of Java is not required. Please send any bugs, questions, comments, or suggestions to email will be answered.
Suggested citation:  The citations below conform to the styles used by the National Library of Medicine and the American Psychological Association, respectively.
  1. Eng J. ROC analysis: web-based calculator for ROC curves. Baltimore: Johns Hopkins University [updated 2014 March 19; cited <date>]. Available from: http://www.jrocfit.org.
  2. Eng, J. (n.d.). ROC analysis: web-based calculator for ROC curves. Retrieved <date>, from http://www.jrocfit.org.
Acknowledgment:  This web page contains JROCFIT and JLABROC4, JavaScript programs for calculating receiver operating characteristic (ROC) curves. JROCFIT performs calculations for discrete ratings data, and JLABROC4 performs calculations for continuously distributed data. JROCFIT and JLABROC4 are direct translations of the ROCFIT and LABROC4 programs, respectively. The latter two were Fortran programs developed by the late Charles Metz and colleagues at the University of Chicago. JROCFIT and JLABROC4 reproduce all output of the original programs. See below for program translation details.

Data Format:  Format 1   Format 2   Format 3   Format 4   Format 5  
Number of Rating Categories:       (Not needed for example data or for Format 5.)
Input Data:  (paste or enter) Program Output:  (may be copied and pasted into other programs)
ROC Curve Summary Statistics: Points for Plotting:  (copy & paste to Excel)
 
ROC Curve Type:   Fitted   Empirical

Key for the ROC Plot
RED symbols and BLUE line:  Fitted ROC curve.
GRAY lines:  95% confidence interval of the fitted ROC curve.
BLACK symbols ± GREEN line:  Points making up the empirical ROC curve (does not apply to Format 5).

 
Exporting the ROC plot to Word or Excel:  Due to limitations of web technology, there is no one-step method for exporting the ROC plot to Microsoft Word or Excel. However, two methods are available for exporting:
  1. Select all of the text in the "Points for Plotting" field, which is located to the right of the graph above. Copy and paste this text into Microsoft Excel. In Excel, create a graph from the data by usual methods. This is a good way to obtain a publication-quality graph of the ROC curve.
  2. Copy a snapshot of the browser window by pressing Alt-PrintScreen, switch to the Microsoft Word window, and paste the image by pressing Control-V. In Word, you need to use Format...Picture (or the cropping tool from the Picture toolbar) to crop and scale the image as needed.
 
Program translation details:  This page contains JROCFIT and JLABROC4, programs for fitting receiver operating characteristic (ROC) curves using the maximum likelihood fit of a binormal model. JROCFIT and JLABROC4 are literal JavaScript translations of the Fortran source code for ROCFIT and LABROC4, programs developed and maintained by the late Dr. Charles Metz and his colleagues at the University of Chicago. During translation, data input routines were added to JROCFIT and JLABROC4 in order to provide a more convenient user interface. The translation was performed with kind permission from Dr. Metz, but neither he nor his colleagues were otherwise involved in the translation, nor do they share any responsibility for the translation's accuracy. While the translation was performed as carefully as possible, the author and Johns Hopkins University assume no responsibility for the accuracy of the programs' operation, regardless of cause.
 (Page last updated: 23 March 2017)