473,772 Members | 2,272 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

Calculating the log of a number

How do I calculate the log of a number? Don't tell me to use log in
cmath; I'm trying to learn complex math in C++. Got any tips/ideas on
how to do this? Thanks for the help!!!

Sep 16 '05
21 8605
"Richard Herring" writes:

Osmium:
That's kind of what it does. The link I posted was the table of contents
for a chapter. You can navigate forward, to p.67 IIRC and find a series.
I think this is a Tschebychev (sp?) expansion. AMS 55 Was a monumental US
work of the 1930's to keep "computers" , back when computers were people,
employed during the depression. Urban Legend? You decide.


UL. Preliminary planning started in 1952, active work started 1956, first
published 1964.
I have the book
and it is physically very imposing.


I commend the Prefaces and Foreword to you. They contain dates ;-)


After being chastised I read the front matter and then realized that I had
already read it sometime in the past, but reading it again didn't change my
opinion. But I didn't make myself clear, I actually had in mind the actual
tabular data, not the physical book with its organization and extra matter
(this thread is actually about the extra matter). IOW, I visualized the
firing tables for the big guns in WW II - artillery and naval - were
computed by these WPA log tables. I still think so. A search for wpa and
ams55 hits a pay site at the one nice hit. A search for wpa and "ams 55"
hits a power point presentation which contains this:

Math tables project (NY 1938-46)
o Works Project Administration
o 37 volumes issued, trig, exp, log, etc.

here's a link to the presentation. I viewed it as HTML so I didn't get all
the "good" out of it.

http://www.google.com/search?num=20&...a+%22ams+55%22

I also found there is a recent book on this very subject. Unfortunately my
library doesn't have it. And by the time they got it on loan I would be off
on some other even more wonderful tangent.

I tried a Usenet search too, and it yielded surprisingly little, but there
is one interesting thread, which is a spin off form the book I mentioned.
It degenerated into a discussion of women being treated so shabbily.
Sep 17 '05 #21
"mlimber" wrote:
osmium wrote:
I think this is a Tschebychev (sp?) expansion.


I believe that's actually a Laurent series, which is the complex
generalization of a Taylor series. Tschebychev, AFAIK, has some
polynomials and filter design techniques named after him, but not
series expansions. Perhaps a lurking mathematician can correct me.


I have no intention of starting an argument. But. I based my comment on
the footnote at the bottom of Eqn. 4.1.44, which says "approximat ions in
terms of Chebyshev polynomials" .
Sep 17 '05 #22

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

4
4492
by: Hans Gruber | last post by:
Hi all, I have been struggling with a problem all day, I have been unable to come up with a working solution. I want to write a function which takes 2 unix timestamps and calculates the difference. I want it to return the difference in years, months, days, hours, minutes and seconds (a complete summary). Keeping into account of course that these are 2 real dates, I dont want it to work with 30.475 as an average number of days in a...
5
8807
by: Ron Adam | last post by:
Hi, I'm having fun learning Python and want to say thanks to everyone here for a great programming language. Below is my first Python program (not my first program) and I'd apreciate any feedback on how I might do things differently to make it either more consice, readable, or faster. ie... are there better ways to do it in Python? It won't break any records for calculating pi, that wasn't my goal, learning Python was. But it might...
4
12682
by: John | last post by:
hey all..... alright, I am frusterated to the point of throwing my machine out the window (this board went down, trying to find stuff on google, this has been a nightmare) so I hope you guys can help me with a solution. This is what I am trying to do: Pretty much, there are two dates in my database, a start date, and an end
5
11953
by: sugaray | last post by:
Hi, my problem with calculating the size of an array is when I pass an array as a parameter to a function which perform the calculation, the result never comes right, like below: int SizeOfArray(int a) { return (sizeof(a)/sizeof(a)); } main() { int a={1,2,3}; printf("%d\n",SizeOfArray(a));
3
12940
by: Ron Vecchi | last post by:
I need to calculate the age of a person based on a DateTime BirthDate I was thinking TimeSpan ts = DateTime.Now - BirthDate; //I can get the days but not years. // I could check each year from their year of birth, count the days in the year and compare with the days returned from timespan
3
5346
by: Miller | last post by:
Hi, Can someone tell me how to calculate MFLOPS for the following C# code (on a Pentium 4 2.0 Ghz)? for (i=0; i<n; i++) { for (j=0; j<n; j++) { for (k=0; k<n; k++)
0
2006
by: hlam | last post by:
Help - Calculating the total of a column in a data grid -- when data grid is part of Master-Detail set-up I have setup a Master-Detail form using Visual Studio.Net. A ListBox is the (Master) and contains a list of dates. The data grid (Details portion) contains the details for a selected date (namely, a list of work codes and hours spent). I am trying to total the number of hours in the datagrid
10
3786
by: Lisa | last post by:
In translating the formula for calculating lottery odds for various conditions into a Visual Basic Program, I have apparently missed something in that I get errors in the part of the calculation where the number of ways of failure (pFal) is calculated Both errors happen in the code section x1 = Draw - MatchesReq x2 = Field - Selections For Counter = 1 To (Draw - MatchesReq - 1) x1 = x1 * (Draw - MatchesReq - Counter)
4
2091
by: =?Utf-8?B?TmF2YW5lZXRoLksuTg==?= | last post by:
Say I have a class like, class Sample { public decimal first = 10; public decimal second = 20; } I have initialized it
1
3550
by: cmb3587 | last post by:
My code runs fine for the most part...the only time it fails is when I type in a negative to end the array. I don't want the negative number to be included in the array and I thought that is what the while loop in the getNums method does. However, it is including this negative number when calculating the avg and it is doing something weird to the median. When the array end itself because the max size has been reached everything works fine. ...
0
9454
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it. First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
0
10261
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed. This is as boiled down as I can make it. Here is my compilation command: g++-12 -std=c++20 -Wnarrowing bit_field.cpp Here is the code in...
0
10104
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth. The Art of Business Website Design Your website is...
1
10038
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
0
9912
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
1
7460
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules. He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms. Adolph will...
0
6715
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one. At the time of converting from word file to html my equations which are in the word document file was convert into image. Globals.ThisAddIn.Application.ActiveDocument.Select();...
1
4007
by: 6302768590 | last post by:
Hai team i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
2
3609
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.