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发表于 2004-9-26 20:43:37
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BESSELJ Bessel function of the first kind.
J = BESSELJ(NU,Z) is the Bessel function of the first kind, J_nu(Z).
The order NU need not be an integer, but must be real.
The argument Z can be complex. The result is real where Z is positive.
If NU and Z are arrays of the same size, the result is also that size.
If either input is a scalar, it is expanded to the other input's size.
If one input is a row vector and the other is a column vector, the
result is a two-dimensional table of function values.
J = BESSELJ(NU,Z,1) scales J_nu(z) by exp(-abs(imag(z)))
[J,IERR] = BESSELJ(NU,Z) also returns an array of error flags.
ierr = 1 Illegal arguments.
ierr = 2 Overflow. Return Inf.
ierr = 3 Some loss of accuracy in argument reduction.
ierr = 4 Complete loss of accuracy, z or nu too large.
ierr = 5 No convergence. Return NaN.
Examples:
besselj(3:9,(0:.2:10)') generates the entire table on page 398
of Abramowitz and Stegun, Handbook of Mathematical Functions.
MEMBRANE uses BESSELJ to generate the fractional order Bessel
functions used by the MathWorks Logo, the L-shaped membrane.
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