Suggested Procedure For Executing ISO Brightness Contour Maps

by Jack E. Gross

Notice to readers.  The download features discussed in this article are no longer available from this website.  The WORKSHEET, DATA, and GEMCAD FILES may be obtained by E-MAIL from the USFG NEWSLETTER'S EDITOR, Jack Gross, at

The ISO BRIGHTNESS CONTOUR MAP procedure in this webpage is intended to supplement the content of Paul A. Head’s article in the December, 1998 issue of the United States Faceting Guild’s Newsletter. Due to space allocation in the newsletter, much of Paul’s original draft could not be included. The material in this webpage hopefully fills in those missing elements and, in addition, supplies additional “how-to-do-it” suggestions. Some of the procedures in Paul’s newsletter article will not be repeated in this webpage. Thus, the webpage reader may find it helpful to consult the newsletter article for additional help. This ” how-to-do-it” supplement should actually be a “how-I-would-do-it” supplement because it attempts to go into some detail on how I (as a total novice to the whole procedure and sort of “beta tester” for Paul’s article) would execute the ISO procedure by using the materials offered in this webpage. Thus, Paul in no way is to be held accountable for my suggested procedure.

The suggestions in this webpage are not intended to imply that they are the only way to execute the procedure. Thus, these suggestions should be considered only as a general example of procedures that I followed and hopefully will get you up and running on the ISO mapping procedure. Those readers who are adept at use of the various software programs will no doubt find alternative approaches.

The first step is to set up a directory in your computer in which the processing software and data files will be stored. Since several of the software routines contain a path statement which tell the computer where to find needed information, I set up a directory that resulted in the shortest possible path statement. To follow my example, create a directory called ISOMAP directly under the C drive (i.e., C:\ISOMAP\).

You are now ready to install processing software and data files. Since I had already installed LOTUS 1-2-3 spreadsheet software program in the default directory used by LOTUS, I reinstalled the LOTUS software in the C:\ISOMAP\ directory. This is not an absolute requirement, but if I had not done this reinstallation process, it would have been necessary to install all of the other software programs and data files in the LOTUS default directory. I simply wanted a “pure” ISO map execution directory. I am not familiar with other spreadsheet software programs but suspect that the same directory setup procedure would be followed as in my LOTUS example. LOTUS 1-2-3 (and I assume other spreadsheet programs) created a bunch of sub-directories under the primary directory C:\ISOMAP\, but, with one exception that is commented on below, that is of no concern to our procedure.

So, at this point in the procedure you should have LOTUS 1-2-3 installed in the C:\ISOMAP\ directory.

The other software program that is required to execute the ISO mapping procedure is Robert Strickland’s program called GEMRAY. Follow the GEMRAY installation procedures to place the GEMRAY program in the C:\ISOMAP\ directory. The GEMRAY software is not supplied in the files to be downloaded from this webpage.

That’s it for software. You will note in Paul’s newsletter article that he refers to several of Strickland’s gem-related programs that are useful for examining gemstone properties, but those programs are not addressed in this webpage procedure.

The next step is to install complete ready-to-run LOTUS worksheets that Paul supplied me. You can download these worksheets as examples and use them for practice (download each file by clicking on the words that are underlined and follow your software’s directions for storing the files). Then, as happened to me, if you run afoul of computer gremlins, you can download the worksheets again and start over with no damage done. One of the worksheets is MAP1006 and the other isMAP2034. One of the sub-directories that LOTUS created under the C:\ISOMAP\ directory is named WORK and a sub-sub-directory under WORK is named 123 (i.e., C:\ISOMAP\WORK\123\). This 123 sub-sub-directory is where you want to install these worksheets when you download them from this webpage. You will note that these two worksheets are numbered 1060 and 2034. These two numbers are the numbers for the Standard Round Brilliant and Eight Main Oval in GEMLIB and GEMCAD (with the leading zero in each case left off). Thus, these numbers are only used to identify which diagram the worksheets and data files are associated with.

The next step is to install the data files that contain the basic crown and pavilion angles for computing the ISO maps. In Paul’s newsletter article these files are called batch files that are formatted according to GEMRAY requirements, as discussed in the newsletter article under Step No. 1. In this webpage, BAT1006 andBAT2034 are the two batch files that were used to create the LOTUS worksheets called MAP1006 and MAP2034. You want to install the BAT1006 and BAT2034 files in the C:\ISOMAP\ directory when you download them from this webpage. These two batch files are ready to be used without any editing or other modifications.

The final two files that must be installed in the C:\ISOMAP\ directory are the GEMCAD files for the Standard Round Brilliant (1006.GEM) and the Eight Main Ova (2034.GEM). Download these two files and store them in the C:\ISOMAP\ directory.

That’s it for data installation. You are now ready to start the ISO map computation procedure.

The first step is simple. If you are using Windows98 as I do, go to WINDOWS DESKTOP and click on START, click on PROGRAMS, and click on MS-DOS PROMPT. This series of selections should open the DOS-prompt window. With the cursor at the C:\windows> prompt-line, type CD C:\ISOMAP then press ENTER. When the C:\ISOMAP> prompt-line appears, type BAT1006 then press ENTER. The BAT1006 batch file will begin to automatically execute. This computing step creates another batch file called GEMRAY.LOG which will be automatically stored in the C:\ISOMAP\ directory when the computing is finished. Depending on your computer capacities, this step in the ISO map computing procedure can require from 15 to 30 minutes. There is nothing else you have to do to complete this computing phase if it is the first time you execute one of the batch files. HOWEVER, before another batch file is executed (such as BAT2034 or some other similar file that you will be creating), you must manually delete the “old” GEMRAY.LOG file from the C:\ISOMAP\ directory. Don’t forget to do this house cleaning. Use your standard file-deletion procedure to delete this GEMRAY.LOG file from the C:\ISOMAP\ directory.

The next step is more tedious (especially if you are a novice at spreadsheet operation) but is not particularly difficult. The first operation is to display on your monitor one of the LOTUS worksheets that you downloaded from this webpage. Do this by first clicking on the icon that activates the LOTUS software. You should just see a blank worksheet on the screen. To activate one of the worksheets you downloaded, click on FILE, click on OPEN, and go through a selection sequence until the 123 directory shows in the LOOK IN window (be sure that the 123 directory is the one that is in the path C:\ISOMAP\WORK\123\ and not the one in the path C:\ISOMAP\123\). If you have the correct directory, you should see the files MAP1006 and MAP2034 in the large window. For your first experiment, highlight MAP1006 and click on OPEN. You should then see the MAP1006 worksheet displayed on the screen. The worksheet will have three sections, an ISO MAP, a DATA ARRAY and a MACRO. In the far left section of the worksheet will be the ISO MAP. In the middle of the worksheet will be the DATA ARRAY that was used to create the ISO MAP (created in a prior execution of the ISO mapping routine). In the far right section of the worksheet will be the MACRO that does two things; (1) The MACRO extracts information out of the BAT1006 file and stores it in the DATA ARRAY; (2) The MACRO extracts information out of the DATA ARRAY and stores it in the ISO MAP.

To continue your first execution of the ISO mapping procedure, do the following: First, move the worksheet in the window until part of the DATA ARRAY and part of the ISO MAP are displayed (this is not a required part of the execution procedure but is done only to show what happens to the worksheet when the MACRO is executed). Then click on EDIT (at the top of the screen), click on SCRIPTS & MACROS, click on RUN, and then check the MACRO button. In the large window you will see a list of items. Arrow down until you see a line that contains \A. Highlight this line, then click on STEP. A window titled MACRO TRACE should have appeared on the screen. Start execution of the MACRO by repeatedly pressing the space bar. Each time the space bar is pressed you will see one short section of the MACRO executed. After the short section “reDATA” is executed you will see the current DATA ARRAY erased. This old DATA ARRAY is erased in order to provide a storage location for the new DATA ARRAY you are in the process of creating. As you continue to press the space bar, you will shortly observe the highlight moving through the section of the MACRO containing “C:\ISOMAP\GEMRAY.LOG”. After the highlight passes through this section of the MACRO, you will see a new DATA ARRAY fill in the area where the old DATA ARRAY was stored. At this point there is no further need to observe the step-by-step activity of the MACRO so click on the CONTINUE EXECUTION box. The MACRO will then complete selecting data from the new DATA ARRAY and entering it into the new ISO MAP. On subsequent executions of this MACRO, it is not necessary to observe the step-by-step process so do not click on the STEP box.

That’s it. You have completed the computerized portion of the ISO mapping procedure and you should have created a worksheet with new numbers (Since you actually used the BAT1006 file to recreate the MAP1006 worksheet, you will see no changes in the DATA ARRAY or the ISO MAP. You only replaced the old numbers with identical new numbers. But when you execute the procedure with a different BAT file as suggested below, you will see the numbers change).

The only remaining steps are to print the ISO MAP and draw the contour lines. To print the ISO CONTOUR MAP, click on FILE, click on PRINT, then in the PRINT TO window select the printer you want to use, then check the SELECTED RANGE box (you should see OUTPUT displayed in the SELECTED RANGE window), then click on PRINT.

You must draw in the contour lines by hand. Sorry about that but we haven’t found a PC-suitable computer program that will automatically do the job. Any suggestions will be appreciated.

Now to branch out on your own. There is very little you have to do to produce ISO maps for other GEMCAD designs that you are interested in.

First, you must copy a GEMCAD file (for the design you are interested in) from GEMCAD into the C:\ISOMAP\ directory. In Windows95 and 98, follow the standard procedure for copying and moving files from one directory to another directory. For example, copy the Octagonal Cushion (04012.GEM) from GEMCAD into the C:\ISOMAP\ directory.

Second, you must modify the batch file that contains the GEMRAY command lines. The easiest way to do this is to modify a batch file that is already available, in this case either BAT1006 or BAT2034. Either one will do but for this exercise use BAT1006. I use the WORDPAD option in WORDPERFECT. Click on the WORDPAD icon, click on FILE, click on OPEN, use the file selection process to show the files in C:\ISOMAP\, highlight BAT1006, and click on OPEN. You should see the BAT1006 file listed on the screen. Click on EDIT, click on REPLACE. In the FIND WHAT window, type 1006. In the REPLACE WITH window, type the numerical part of the stone diagram that you transferred from GEMCAD into the C:\ISOMAP\ directory. For example if you transferred the Octagonal Cushion, whose GEMLIB and GEMCAD number is 04012, then type 4012 (the leading zero can be eliminated) in the REPLACE WITH window. You should see that all of the 1006 entries in the file have been changed to 4012. If the refractive index for the 4012 cut is different from the refractive index of the 1006 cut, then you must change the refractive index. For example, if the refractive index for the 4012 cut is 1.54, repeat the FIND WHAT/REPLACE WITH sequence but use 2.15 for FIND WHAT and 1.54 for REPLACE WITH. You should see that all of the 2.15 entries in the file have been changed to 1.54 Then click on FILE, click on SAVE AS, in the FILE NAME window type BAT4012, click on SAVE, then close the file.

That’s it. Nothing else has to be modified. You are ready to create the ISO map for the 4012 cut. Follow the sequence previously outlined for executing the 1006 cut (DON’T FORGET TO DELETE THE OLD GEMRAY.LOG FILE FROM THE C:\ISOMAP\ DIRECTORY.

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