Logo by mauxuam - Contribute your own Logo!

END OF AN ERA, FRACTALFORUMS.COM IS CONTINUED ON FRACTALFORUMS.ORG

it was a great time but no longer maintainable by c.Kleinhuis contact him for any data retrieval,
thanks and see you perhaps in 10 years again

this forum will stay online for reference
News: Visit the official fractalforums.com Youtube Channel
 
*
Welcome, Guest. Please login or register. October 29, 2020, 12:20:44 PM


Login with username, password and session length


The All New FractalForums is now in Public Beta Testing! Visit FractalForums.org and check it out!


Pages: [1]   Go Down
  Print  
Share this topic on DiggShare this topic on FacebookShare this topic on GoogleShare this topic on RedditShare this topic on StumbleUponShare this topic on Twitter
Author Topic: Strange behaviour found in Developer's release of FractInt for Windows v20.99.8  (Read 1496 times)
0 Members and 1 Guest are viewing this topic.
simon.snake
Fractal Bachius
*
Posts: 640


Experienced Fractal eXtreme plugin crasher!


simon.fez SimonSideBurns
« on: May 16, 2012, 12:41:01 AM »

Hi

I have been playing with fractint's own formula parser for some time and have noticed what I would call a bug in the parsing of the ident function.

Here's the two formulae that I have been using for testing purposes:

Code:
simon0063-A {
  ; Trying to figure out ident
  ;
  z = p = pixel:
  z = fn1(z * z) + p
  |z| < 4
}

simon0063-B {
  ; Trying to figure out ident
  ;
  z = p = pixel:
  t = z * z
  z = fn1(t) + p
  |z| < 4
}

What the formula parser does is asks the user which function they wish to use.  The only difference between formula 63-A and 63-B is the use of a temporary variable t to hold the result of the squaring of z and to pass that to the formula.  If I select the function ident (which stands for identical), whatever is passed to the formula is what should be returned, but here's the resulting picture of each formula:

formula 63-A:


formula 63-B:


As you can see, 63-B shows the standard mandelbrot as you would expect, but 63-A shows something completely different.  It is as if the multiplication is being completely ignored (and one instance of z is returned by the function).

I've tried this in the dos based 20.0 version via dosbox and both types of formula show the mandelbrot image correctly.

Shame I've only just noticed this as I was running a batch file creating lots of images (as per one of my previous posts) and had the original style of syntax in the formula for that (which means that every permutation where the formula used the ident function has generated an incorrect picture).

Simon
Logged

To anyone viewing my posts and finding missing/broken links to a website called www.needanother.co.uk, I still own the domain but recently cancelled my server (saving ú30/month) so even though the domain address exists, it points nowhere.  I hope to one day sort something out but for now - sorry!
Pages: [1]   Go Down
  Print  
 
Jump to:  

Related Topics
Subject Started by Replies Views Last post
FractInt under Windows (Beta-5) Announcements & News Nahee_Enterprises 4 5633 Last post September 27, 2010, 10:33:21 PM
by Nahee_Enterprises
fractint for windows problem? Help & Support tomot 1 1493 Last post April 25, 2011, 12:43:07 AM
by wmauzey
Using color maps from Windows Fractint Chaoscope wmauzey 10 3466 Last post September 19, 2013, 05:34:02 AM
by Nahee_Enterprises
Does anyone know how to SIMPLY get 16-bit fractint DOS to go on Windows 7? FractInt « 1 2 » fracmonk 23 9923 Last post June 02, 2017, 09:55:00 AM
by stardust4ever
strange behaviour of light placement in fish eye view Bug Reporting taurus 4 692 Last post October 05, 2013, 11:44:29 AM
by lukesleftleg

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines

Valid XHTML 1.0! Valid CSS! Dilber MC Theme by HarzeM
Page created in 0.115 seconds with 29 queries. (Pretty URLs adds 0.009s, 2q)