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Dataplot Vol 2 Vol 1

LOBACH

Name:
    LOBACH (LET)
Type:
    Library Function
Purpose:
    Compute the Lobachevski's integral.
Description:
    The Lobachevski's integral is defined as:

      f(x) = INTEGRAL[LOG(ABS(COS(t)))dt], x >= 0 and where the integral is defined from 0 to x

    Dataplot computes this function using ACM Algorithm 757 (see Reference: below).

Syntax:
    LET <y> = LOBACH(<x>)             <SUBSET/EXCEPT/FOR qualification>
    where <x> is a non-negative number, variable or parameter;
                <y> is a variable or a parameter (depending on what <x> is) where the computed Lobachevski's integral values are stored;
    and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
    LET A = LOBACH(2)
    LET A = LOBACH(X)
    LET X2 = LOBACH(X) FOR X1 = 0.1 0.1 3.0
Default:
    None
Synonyms:
    None
Related Commands:
    ABRAM = Compute the Abramowitz integral.
    CLAUSN = Compute the Clausen integral.
    DEBEYE = Compute the Debeye function.
    EXP3 = Compute the cubic exponential integral.
    GOODST = Compute the Goodwin and Stanton integral.
    SYNCH1 = Compute the synchrotron radiation function.
    SYNCH2 = Compute the synchrotron radiation function.
    STROM = Compute the Stromgren integral.
    TRAN = Compute the transport integral.
Reference:
    "ACM Transactions of Mathematical Software", Allan MacLead, Vol. 22, No. 3, September, 1996, pp. 288-301.
Applications:
    Special Functions
Implementation Date:
    1999/6
Program:
    TITLE AUTOMATIC
    PLOT LOBACH(X) FOR X = 0 0.01 10

    plot generated by sample program

Date created: 6/5/2001
Last updated: 4/4/2003
Please email comments on this WWW page to alan.heckert@nist.gov.