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Member of the advanced class.

Syntax

iv = besseli(v, x)

iv = besseli(v, x, 1)

[iv, error] = besseli(v, x)

[iv, error] = besseli(v, x, 1)

Description

Computes the modified Bessel function of the first kind of a given order.

Details

Examples

Inputs

Name	Description
v	Specifies the order of the Bessel function. v is a real, double-precision, floating-point, positive scalar, vector, or matrix.
x	Specifies the value for which you want to compute the Bessel function. x is a real or complex, double-precision, floating-point scalar, vector, or matrix.
1	Scales the computation. besseli(v, x, 1) scales besseli(v, x) by exp(-abs(real(x))).

Outputs

Name	Description
iv	Returns the modified Bessel function of the first kind. iv is a real or complex, double-precision, floating-point scalar, vector, or matrix.
error	Returns error information about the evaluation of the Bessel function. error is an integer that can return the following values. 0 Indicates that no error occurred. 1 Indicates that you specified invalid inputs. 2 Indicates that the result is too large for the data type of iv. Use the scaling option 1. 3 Indicates that LabVIEW achieved less than half the machine accuracy in the calculation because |x| or v is greater than approximately 1.3E8. 4 Indicates that the result is meaningless because |x| or v is greater than approximately 1.8E16. 5 Indicates that the calculation did not reach the termination condition so LabVIEW did not complete the calculation.

Details

besseli(v, x) solves the following equation: x²*w''+x*w'-(x²+v²)*w = 0.
The following equation is a well-known representation for besseli(v, x): besseli(v, x) = ((1/2)*x)^v*sum((z²/4)^k/(k!*gamma(v+k+1)), k, 0, inf).
If x is a scalar, LabVIEW sets x to a vector of the same size as v whose elements all equal the value you specified for x. If y is a scalar, LabVIEW sets y to a vector of the same size as v whose elements all equal the value you specified for y. If x and v are vectors of the same orientation, LabVIEW returns a vector of Bessel functions for corresponding input values. For example, if x = [1, 2] and v = [3, 4], LabVIEW returns [besseli(1, 3), besseli(2, 4)]. If x and v are vectors of opposite orientation, LabVIEW returns a matrix of Bessel functions for each combination of input values. For example, if x = [1, 2] and v = [3; 4], LabVIEW returns [besseli(1, 3), besseli(1, 4); besseli(2, 3), besseli(2, 4)].

Examples

X = [0:0.01:2];
IV = besseli(2.75, X);
plot(X, IV)

Related Topics

airy
besschk
bessel
besselh
besselj
besselk
bessely