Dataplot Vol 2 Vol 1

# HV

Name:
HV (LET)
Type:
Library Function
Purpose:
Compute the Struve function.
Description:
The Struve function can be expressed as:

where v is the order of the Struve function and is the gamma function.

Dataplot computes this function using the STVH0, STVH1, and STVHV routines from "Computation of Special Functions" (see the Reference section below).

Syntax 1:
LET <y> = HV(<x>,<v>)             <SUBSET/EXCEPT/FOR qualification>
where <x> is a number, variable or parameter;
<v> is a number, parameter, or variable;
<y> is a variable or a parameter (depending on what <x> and <v> are) where the computed Struve function values are stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.

Dataplot supports the Struve function for non-negative real x and for orders between -8.5 and 12.5. This syntax is used for arbitrary order.

Syntax 2:
LET <y> = H0(<x>)             <SUBSET/EXCEPT/FOR qualification>
where <x> is a number, variable or parameter;
<y> is a variable or a parameter (depending on what <x> is) where the computed Struve function values are stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.

Dataplot supports the Struve function for non-negative real x. This syntax is used for the Struve function of order 0.

Syntax 3:
LET <y> = H1(<x>)             <SUBSET/EXCEPT/FOR qualification>
where <x> is a number, variable or parameter;
<y> is a variable or a parameter (depending on what <x> is) where the computed Struve function values are stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.

Dataplot supports the Struve function for non-negative real x. This syntax is used for the Struve function of order 1.

Examples:
LET A = HV(2.3,1)
LET A = HV(X,A1)
LET X2 = HV(X1,4) FOR X1 = 0.1 0.1 3.0
Default:
None
Synonyms:
None
Related Commands:
 LV = Compute the modified Struve function. BESSJN = Compute the Bessel function of the first kind. BESSYN = Compute the Bessel function of the second kind. BESSIN = Compute the modified Bessel function. BESSKN = Compute the modified Bessel function of the third kind.
Reference:
"Computation of Special Functions", Shanjie Zhang and Jianming Jin, John Wiley and Sons, 1996, chapter 11.

"AMS 55: Handbook of Mathematical Functions", Abramowitz and Stegun, Eds., Washington, DC, National Bureau of Standards, 1964.

Applications:
Special Functions
Implementation Date:
1997/12
Program:
MULTIPLOT 2 2
MULTIPLOT CORNER COORDINATES 5 5 95 95
TITLE ORDER 0
PLOT HV(X,0) FOR X = 0 0.01 10
TITLE ORDER 1
PLOT HV(X,1) FOR X = 0 0.01 10
TITLE ORDER 2
PLOT HV(X,2) FOR X = 0 0.01 10
TITLE ORDER 3
PLOT HV(X,3) FOR X = 0 0.01 10
END OF MULTIPLOT
MOVE 50 97
JUSTIFICATION CENTER
TEXT STRUVE FUNCTIONS

Date created: 6/5/2001
Last updated: 4/4/2003