Advanced Charting - Formulas
EFS Formulas
eSignal Support Forums and File share
Adding, Changing, Editing Formulas
Formula Engine
Formula Encryption
Formula Wizard
Studies vs. Formulas
Technically, there is no difference between the words "study" and "formula." Both words are used in the industry to refer to technical analysis/technical indicators that, when applied to the "raw" market data, help the trader make sense of the numbers (that is, buy or sell, go long or short?). In fact, we use the word "study" for all of the types of technical analysis we now have available in eSignal.
In reference to eSignal, we have many studies that are included with the installation. At the bottom of the Chart Options menu you will see several categories of studies, Basic Studies, Add-On Studies and a Formulas folder containing many categories of eSignal Formula Script (EFS) studies. The Basic Studies are built-in to the software and may not be modified by the user. However, most of them have user-defined parameters that may be changed through the Edit Studies option under the Chart Options menu. The Add-On Studies, are subscription based studies developed by 3rd party developers. There is also a group of free Add-On Studies to chose from.
EFS Formulas
The EFS formulas in the Formulas folder are open source code for the most part. Users may make code modifications to these formulas as needed. It's recommended to make a copy of the formula with a unique name to maintain the original copy in the event you need to revert back to the original code.
All EFS formulas are written in JavaScript, a well documented and widely used programming language. The more you know about JavaScript, the more you will be able to write and modify your own studies. If you have an interest in understanding or writing your own formulas, you will need to have a working knowledge of the JavaScript language. For reference documentation on EFS, please visit our EFS KnowledgeBase. Here you will find a collection of information to assist you. There are many reference documents links to other helpful JavaScript resources.
eSignal Support Forums and File Share
eSignal does not provide support on a one-on-one basis in regards to formulas. We will provide direct support with EFS inquiries through the public forums when ever possible. The main benefit to posting questions and requests for help in the public forums is that the information becomes available to the search feature of the forums. By searching on key words related to your questions, you may find answers and code examples from previous discussions in the forums. Please try the search feature first. If you don’t find what you need, please post your question/request in one of the public forums.
We encourage eSignal users to register for File Sharing and post their requests in our eSignal Support Forums. There are several user groups on the Internet. First we recommend that you take a look at eSignal Support Forums and File Sharing. You can read and post messages as well as upload and share files with other eSignal users.
Adding, Changing or Editing Formulas
The preferred and recommended way to do this is to use the Formula Editor. This feature of eSignal has many features that help you successfully write EFS formulas. You can open the Formula Editor from the Tools menu under EFS.
If you do not have eSignal open and/or would like to write a formula outside of the Formula Editor, you can write it in a plain text file and save it with a .efs extension.
The Formula Engine Settings Box
To open this, click Tools, EFS then Settings. The settings in that box allow you to control a few aspects of how the formulas perform. The Heap and Stack settings are to allocate the amount of memory the formula engine uses. If you are running Advanced Charts with formulas and are getting crashes, increasing these values may be useful. The other options in that box are the default settings for where the program will look for your formulas and audio files. There are also several performance options available to help increase the efficiency of your formula execution and reduce CPU processing load. The first option allows you to force all formulas to compute on close of each bar rather than tick-by-tick, which helps minimize the amount of CPU processing. Enabling the EFS Performance Monitor allows for the collection of processing information related to specific formulas and EFS functions currently running in your page or layout. Disabling the debugPrint and debugPrintln functions is typically used during EFS formula developing for debugging purposes. Any formulas that have these functions active can reduce formula efficiency and increase CPU usage. This option allows you to quickly disable those functions without having to modify the formula code.
Formula Encryption
To Encrypt your formula, click on Tools - EFS - Encrypt/Decrypt.
Then select the script you wish to encrypt.
There are two types of encryption, Basic and Enhanced. The Enhanced encryption is new in version 7.9 and later. Formulas encrypted with Enhanced Encryption will only be compatible with eSignal versions 7.9 and later. Formulas encrypted with Basic encryption prior to version 7.9 will still be compatible with all future versions of eSignal.
If Basic Encryption is selected, enter a password, and again to verify. If you like you can also include your email address, but that is optional. Then click OK. This encryption type encrypts the source code file that was selected.
After it is done encrypting, click Close, and the file can now only be opened in the editor with a password. Therefore, it is recommended to make a back-up copy of the original source code with a different file name for safe keeping.
If Enhanced Encryption is selected, a new encrypted file is created with the original file name followed by .encrypted.efs. The original source code file is left as is in this case. You may want to rename the new encrypted file to a more desirable file name to remove the .encrypted portion. Once an enhanced encrypted file is created, it cannot be unencrypted as there is no password field during the encryption process. Safeguard the original source code file to retain the original code. Once the encryption has completed, click on Close.
Formula Wizard
The Formula Wizard tool assists in the creation of NEW studies, color indicators of studies, and alerts on studies. Note that modifications to existing studies or alerts should be done with the EFS Editor (on the eSignal Toolbar, click Tools, then Editor). The Formula Wizard is a tool developed primarily for the creation of new studies and alerts based upon the studies. The Formula Wizard can also be used to edit existing studies and/or alerts that were originally created with the Wizard.
A basic understanding of the structure of an EFS formula is helpful in making full use of the Formula Wizard. We currently have a "How-to" document for the Formula Wizard available for download in Microsoft® Word* format.
*Microsoft and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries