Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Traditional navigation by slide rule
    From: Bob Goethe
    Date: 2016 Oct 28, 12:59 -0700

    I see that Excel 2013 has an LN() function available to it...but the flavor of Visual Basic which I have integrated with my graphics program, CorelDraw, does not support this function per se.

    I do see that there is a derived function that Corel supports that looks like this:

         Logarithm to base N:

         LogN(X) = Log(X) / Log(N)

    I don't (yet) know enough about natural logarithms to know how, if at all, this "LogN()" relates to Excel's "LN()".

    Presumably if need be, I could use Excel to generate a list of coordinates where I would want to lay down hash marks for a scale.  But getting Corel to do it directly would be more straightforward...if Corel can do it on its own at all, that is.

    I do see that http://www.antiquark.com/sliderule/sim/n3t/virtual-n3-t.html illustrates an Ln scale, and even lets one play around with it.  That will give me an idea of the layout for the scale I should come up with if I can figure out what to feed to an equation to generate it. 

    I think before I get into adding a scale to my slide rule, I am going to have to go back to school on logarithms, so to speak.  The last time I worked with them was 45 years ago.

    Gary, could you work through one rhumb line problem from beginning to end using your equations, so that I have a model to follow as I try and sort out how to do this myself?  It will help me spot elementary errors if I know what the right answer should be to a particular calculation.

    Thanks so much,

    Bob

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site