The Transform Generator (TG) was conceived and written by AAVSO member/observer Gordon Myers in response to a need for an easy-to-use program which will aid the observer in the computation of their transformation coefficients. The AAVSO acknowledges and greatly appreciates Gordon's 100% volunteer effort.
(Transform Generator was originally known as the Photometry Transformation Generation Program (PTGP). The name was changed to Transform Generator (TG) with the release of version 5.5)
TG generates telescope transformation coefficients used in stellar photometry. The program makes the process much easier for users – no longer requiring the extensive use of spreadsheets. The program processes instrument magnitude measurements of standard star reference fields – currently M67 and NGC7790. Instrument magnitude measurements files can be generated using AIP4WIN or MaxIm, or can be downloaded from VPHOT. The program accesses the AAVSO VSP data base in real time to obtain the necessary standard magnitudes (requiring an Internet connection) and calculates all standard transformation coefficients. Users may then plot the results, remove discrepant observations, finalize and save a set of transformations. The program also enables the user to compare different sets of transformations (typically taken at different times and/or days), average them and then export a final transformation set for use.
TG requires the use of Python 2.7 along with several additional libraries. It runs on Windows, Apple, and LINUX computers. The simplest installation uses an integrated set of Python software libraries known as anaconda (https://store.continuum.io/cshop/anaconda/ ). Following the procedures below will ensure all of the necessary software is installed on your computer.
Operation requires an Internet connection.
First download this zip file (TG_V5.7_installation_files.zip ) which contains two files used in all the installations. The two files are –
Updating an existing PTGP V4.0 or TG V5.x installation: If you previously installed PTGP or TG, installation only requires you copy the TransformGenerator_V5.7.pyw file to the Photometry directory. To create a new desktop icon to start the program, navigate to the TransformGenerator_V5.7.pyw file using Windows Explorer. Right click on the file name, and select “Send to” > "Desktop (create shortcut)".
Installing into Existing Python Installations: There are many different Python 2.7 installation alternatives – not fully compatible with each other. If you have one installed, try to run TG in that environment. If it does not run successfully, the best approach is probably to do a clean installation using the “Anaconda” environment below.
New Installations: TG runs with the standard Python 2.7 suite known as Anaconda which contains the various libraries needed to complement the basic Python 2.7 package.
If you are on a 64-bit Windows machine, download http://repo.continuum.io/archive/Anaconda-2.0.1-Windows-x86_64.exe  and run the program, accepting all defaults – except be sure you install it for “All Users” – not “Just Me”. This will install Anaconda into the folder c:/Anaconda.
If you don’t have a 64-bit computer, visit https://store.continuum.io/cshop/anaconda/  to locate a compatible installation file. Stick with Anaconda version 2.0.1. Experience unfortunately has shown that new releases sometimes have errors that might prevent TG from running properly.
After successful installation of Anaconda, navigate to c:/Anaconda using Windows Explorer and create a new subdirectory “Photometry” – e.g. c:/Anaconda/Photometry. Copy the program TransformGenerator_V5.7.pyw and the demonstration file M67_T17_20140330_Photometry_Demo_instrument_mags.txt into the Photometry directory. Then create a desktop icon to start the program by navigating to the TransformGenerator_V5.7.pyw file in c:/Anaconda/Photometry; then right click on the file name, and select “Send to” > "Desktop (create shortcut)".
Double click the icon to start the program. If Windows requests you identify what program to use to execute TransformGenerator_V5.7.pyw, navigate and select c:/anaconda/pythonw.exe.
For operational details see the TransformGenerator_V5.7_Users Guide .
Running TG on a Mac with OS X (v.10.10 – Yosemite) Installed
The new Mac OS X (v.10.10 – Yosemite) release no longer comes with an X11 terminal emulator installed. If you are doing a new install of TG, or if you upgraded your computer to the Yosemite OS release, you must manually install the emulator. To do this, go to xquartz.macrosforge.org , download and install with defaults. Note: This step is NOT required if you have a previous Mac OS installed (e.g. Mavericks).
If, subsequent to following these steps the X11 emulator does not automatically start, start a Mac terminal and enter the command “sudo ln -s /opt/X11 /usr/X11”. Your computer will then ask for your password to make the system update.
Manual installation of the X11 terminal emulator is only required once.
Updating an existing PTGP V4.0, TG V5.x installation: If you previously installed PTGP or TG, installation only requires you copy the TG_V5.7.pyw file to the Photometry folder. Then create a new desktop icon for the Mac. Refer to the paper Create Mac Icon to Start TG v5.7.pdf . Note the first time you use the new icon, it can take over 15 seconds to launch the program. Subsequently the program will open rapidly.
Installing into Existing Python Installations: There are many different Python 2.7 installation alternatives – not fully compatible with each other. If you have one installed, try to run TG in that environment. If it does not run successfully, the best approach is probably to do a clean installation using the Anaconda environment below.
New Installation: On a Mac, Anaconda version 1.9.1 must be used. TG will not run properly with the newer Anaconda versions 1.9.2 or 2.0.1 on a Mac.
If you have a 64-bit Mac, download Anaconda v. 1.9.1 from http://repo.continuum.io/archive/Anaconda-1.9.1-MacOSX-x86_64.pkg  and install it by selecting the downloaded package. This installation creates a new top-level folder “/anaconda” containing all the Python software required to run TG. Do the following to ensure Anaconda is installed properly -
During install this window appears:
Select “Install on a specific disk…”
Select Macintosh HD
Select “Continue” to proceed. The anaconda folder will be placed on the Macintosh HD drive as a top level folder.
The installation process will continue to completion.
This installation package supports OS X on a 64 bit Mac. If you have a different Mac computer, visit https://store.continuum.io/cshop/anaconda/  to locate other available downloads. Be certain to download version 1.9.1.
After successful installation of Anaconda, navigate to /Anaconda using Finder and create a new folder “Photometry” – e.g. /Anaconda/Photometry. Copy the program TransformGenertor_V5.7.pyw and the demonstration file M67_T17_20140330_Photometry_Demo_instrument_mags.txt into the Photometry folder.
Creating a new desktop icon for the Mac takes some extra work. Refer to the paper Create Mac Icon to Start TransformGenerator_V5.7.pdf . Double click the icon to start the program. Note the first time you use the new icon, it can take over 15 seconds to launch the program. Subsequently the program will open rapidly.
For operational details see the TransformGenerator V5.7 Users Guide 
The User's Guide is available here:
Send questions and comments to Gordon Myers - gordonmyers @ hotmail.com
Copyright © 2014.