# Special Functions > Standard library math iterators for special functions.
## Usage ```javascript var ns = require( '@stdlib/math/iter/special' ); ``` #### ns Standard library math iterators for special functions. ```javascript var iterators = ns; // returns {...} ``` The namespace contains the following functions for creating iterator protocol-compliant iterators:
- [`iterAbs( iterator )`][@stdlib/math/iter/special/abs]: create an iterator which iteratively computes the absolute value. - [`iterAbs2( iterator )`][@stdlib/math/iter/special/abs2]: create an iterator which iteratively computes the squared absolute value. - [`iterAcos( iterator )`][@stdlib/math/iter/special/acos]: create an iterator which iteratively computes the arccosine. - [`iterAcosh( iterator )`][@stdlib/math/iter/special/acosh]: create an iterator which iteratively computes the hyperbolic arccosine. - [`iterAcot( iterator )`][@stdlib/math/iter/special/acot]: create an iterator which iteratively computes the inverse cotangent. - [`iterAcoth( iterator )`][@stdlib/math/iter/special/acoth]: create an iterator which iteratively computes the inverse hyperbolic cotangent. - [`iterAcovercos( iterator )`][@stdlib/math/iter/special/acovercos]: create an iterator which iteratively computes the inverse coversed cosine. - [`iterAcoversin( iterator )`][@stdlib/math/iter/special/acoversin]: create an iterator which iteratively computes the inverse coversed sine. - [`iterAhavercos( iterator )`][@stdlib/math/iter/special/ahavercos]: create an iterator which iteratively computes the inverse half-value versed cosine. - [`iterAhaversin( iterator )`][@stdlib/math/iter/special/ahaversin]: create an iterator which iteratively computes the inverse half-value versed sine. - [`iterAsin( iterator )`][@stdlib/math/iter/special/asin]: create an iterator which iteratively computes the arcsine. - [`iterAsinh( iterator )`][@stdlib/math/iter/special/asinh]: create an iterator which iteratively computes the hyperbolic arcsine. - [`iterAtan( iterator )`][@stdlib/math/iter/special/atan]: create an iterator which iteratively computes the arctangent. - [`iterAtan2( y, x )`][@stdlib/math/iter/special/atan2]: create an iterator which iteratively computes the angle in the plane (in radians) between the positive x-axis and the ray from `(0,0)` to the point `(x,y)`. - [`iterAtanh( iterator )`][@stdlib/math/iter/special/atanh]: create an iterator which iteratively computes the hyperbolic arctangent. - [`iterAvercos( iterator )`][@stdlib/math/iter/special/avercos]: create an iterator which iteratively computes the inverse versed cosine. - [`iterAversin( iterator )`][@stdlib/math/iter/special/aversin]: create an iterator which iteratively computes the inverse versed sine. - [`iterBesselj0( iterator )`][@stdlib/math/iter/special/besselj0]: create an iterator which iteratively evaluates the Bessel function of the first kind of order zero. - [`iterBesselj1( iterator )`][@stdlib/math/iter/special/besselj1]: create an iterator which iteratively evaluates the Bessel function of the first kind of order one. - [`iterBessely0( iterator )`][@stdlib/math/iter/special/bessely0]: create an iterator which iteratively evaluates the Bessel function of the second kind of order zero. - [`iterBessely1( iterator )`][@stdlib/math/iter/special/bessely1]: create an iterator which iteratively evaluates the Bessel function of the second kind of order one. - [`iterBeta( x, y )`][@stdlib/math/iter/special/beta]: create an iterator which iteratively evaluates the beta function. - [`iterBetaln( x, y )`][@stdlib/math/iter/special/betaln]: create an iterator which iteratively evaluates the natural logarithm of the beta function. - [`iterBinet( iterator )`][@stdlib/math/iter/special/binet]: create an iterator which iteratively evaluates Binet's formula extended to real numbers. - [`iterCbrt( iterator )`][@stdlib/math/iter/special/cbrt]: create an iterator which iteratively computes the cube root. - [`iterCeil( iterator )`][@stdlib/math/iter/special/ceil]: create an iterator which rounds each iterated value toward positive infinity. - [`iterCeil10( iterator )`][@stdlib/math/iter/special/ceil10]: create an iterator which rounds each iterated value to the nearest power of 10 toward positive infinity. - [`iterCeil2( iterator )`][@stdlib/math/iter/special/ceil2]: create an iterator which rounds each iterated value to the nearest power of two toward positive infinity. - [`iterCos( iterator )`][@stdlib/math/iter/special/cos]: create an iterator which iteratively computes the cosine. - [`iterCosh( iterator )`][@stdlib/math/iter/special/cosh]: create an iterator which computes the hyperbolic cosine for each iterated value. - [`iterCosm1( iterator )`][@stdlib/math/iter/special/cosm1]: create an iterator which computes `cos(x) - 1` for each iterated value. - [`iterCospi( iterator )`][@stdlib/math/iter/special/cospi]: create an iterator which computes the cosine of each iterated value times π. - [`iterCovercos( iterator )`][@stdlib/math/iter/special/covercos]: create an iterator which computes the coversed cosine for each iterated value. - [`iterCoversin( iterator )`][@stdlib/math/iter/special/coversin]: create an iterator which computes the coversed sine for each iterated value. - [`iterDeg2rad( iterator )`][@stdlib/math/iter/special/deg2rad]: create an iterator which converts an angle from degrees to radians for each iterated value. - [`iterDigamma( iterator )`][@stdlib/math/iter/special/digamma]: create an iterator which evaluates the digamma function for each iterated value. - [`iterDiracDelta( iterator )`][@stdlib/math/iter/special/dirac-delta]: create an iterator which iteratively evaluates the Dirac delta function. - [`iterEta( iterator )`][@stdlib/math/iter/special/dirichlet-eta]: create an iterator which iteratively evaluates the Dirichlet eta function. - [`iterEllipe( iterator )`][@stdlib/math/iter/special/ellipe]: create an iterator which computes the complete elliptic integral of the second kind for each iterated value. - [`iterEllipk( iterator )`][@stdlib/math/iter/special/ellipk]: create an iterator which computes the complete elliptic integral of the first kind for each iterated value. - [`iterErf( iterator )`][@stdlib/math/iter/special/erf]: create an iterator which iteratively evaluates the error function. - [`iterErfc( iterator )`][@stdlib/math/iter/special/erfc]: create an iterator which iteratively evaluates the complementary error function. - [`iterErfcinv( iterator )`][@stdlib/math/iter/special/erfcinv]: create an iterator which iteratively evaluates the inverse complementary error function. - [`iterErfinv( iterator )`][@stdlib/math/iter/special/erfinv]: create an iterator which iteratively evaluates the inverse error function. - [`iterExp( iterator )`][@stdlib/math/iter/special/exp]: create an iterator which iteratively evaluates the natural exponential function. - [`iterExp10( iterator )`][@stdlib/math/iter/special/exp10]: create an iterator which evaluates the base 10 exponential function for each iterated value. - [`iterExp2( iterator )`][@stdlib/math/iter/special/exp2]: create an iterator which evaluates the base 2 exponential function for each iterated value. - [`iterExpit( iterator )`][@stdlib/math/iter/special/expit]: create an iterator which evaluates the standard logistic function for each iterated value. - [`iterExpm1( iterator )`][@stdlib/math/iter/special/expm1]: create an iterator which computes `exp(x) - 1` for each iterated value. - [`iterExpm1rel( iterator )`][@stdlib/math/iter/special/expm1rel]: create an iterator which evaluates the relative error exponential for each iterated value. - [`iterFactorial( iterator )`][@stdlib/math/iter/special/factorial]: create an iterator which iteratively evaluates the factorial function. - [`iterFactorialln( iterator )`][@stdlib/math/iter/special/factorialln]: create an iterator which iteratively evaluates the natural logarithm of the factorial function. - [`iterFloor( iterator )`][@stdlib/math/iter/special/floor]: create an iterator which rounds each iterated value toward negative infinity. - [`iterFloor10( iterator )`][@stdlib/math/iter/special/floor10]: create an iterator which rounds each iterated value to the nearest power of 10 toward negative infinity. - [`iterFloor2( iterator )`][@stdlib/math/iter/special/floor2]: create an iterator which rounds each iterated value to the nearest power of two toward negative infinity. - [`iterFresnelc( iterator )`][@stdlib/math/iter/special/fresnelc]: create an iterator which computes the Fresnel integral C(x) for each iterated value. - [`iterFresnels( iterator )`][@stdlib/math/iter/special/fresnels]: create an iterator which computes the Fresnel integral S(x) for each iterated value. - [`iterGamma( iterator )`][@stdlib/math/iter/special/gamma]: create an iterator which iteratively evaluates the gamma function. - [`iterGamma1pm1( iterator )`][@stdlib/math/iter/special/gamma1pm1]: create an iterator which computes `gamma(x+1) - 1` for each iterated value. - [`iterGammaln( iterator )`][@stdlib/math/iter/special/gammaln]: create an iterator which iteratively evaluates the natural logarithm of the gamma function. - [`iterHacovercos( iterator )`][@stdlib/math/iter/special/hacovercos]: create an iterator which computes the half-value coversed cosine for each iterated value. - [`iterHacoversin( iterator )`][@stdlib/math/iter/special/hacoversin]: create an iterator which computes the half-value coversed sine for each iterated value. - [`iterHavercos( iterator )`][@stdlib/math/iter/special/havercos]: create an iterator which computes the half-value versed cosine for each iterated value. - [`iterHaversin( iterator )`][@stdlib/math/iter/special/haversin]: create an iterator which computes the half-value versed sine for each iterated value. - [`iterInv( iterator )`][@stdlib/math/iter/special/inv]: create an iterator which iteratively computes the multiplicative inverse. - [`iterLn( iterator )`][@stdlib/math/iter/special/ln]: create an iterator which iteratively evaluates the natural logarithm. - [`iterLog( x, b )`][@stdlib/math/iter/special/log]: create an iterator which iteratively computes the base `b` logarithm. - [`iterLog10( iterator )`][@stdlib/math/iter/special/log10]: create an iterator which iteratively evaluates the common logarithm (logarithm with base 10). - [`iterLog1mexp( iterator )`][@stdlib/math/iter/special/log1mexp]: create an iterator which iteratively evaluates the natural logarithm of `1-exp(-|x|)`. - [`iterLog1p( iterator )`][@stdlib/math/iter/special/log1p]: create an iterator which iteratively evaluates the natural logarithm of `1+x`. - [`iterLog1pexp( iterator )`][@stdlib/math/iter/special/log1pexp]: create an iterator which iteratively evaluates the natural logarithm of `1+exp(x)`. - [`iterLog2( iterator )`][@stdlib/math/iter/special/log2]: create an iterator which iteratively evaluates the binary logarithm. - [`iterLogit( iterator )`][@stdlib/math/iter/special/logit]: create an iterator which evaluates the logit function for each iterated value. - [`iterPow( base, exponent )`][@stdlib/math/iter/special/pow]: create an iterator which iteratively evaluates the exponential function. - [`iterRad2deg( iterator )`][@stdlib/math/iter/special/rad2deg]: create an iterator which converts an angle from radians to degrees for each iterated value. - [`iterRamp( iterator )`][@stdlib/math/iter/special/ramp]: create an iterator which iteratively evaluates the ramp function. - [`iterZeta( iterator )`][@stdlib/math/iter/special/riemann-zeta]: create an iterator which evaluates the Riemann zeta function for each iterated value. - [`iterRound( iterator )`][@stdlib/math/iter/special/round]: create an iterator which rounds each iterated value to the nearest integer. - [`iterRound10( iterator )`][@stdlib/math/iter/special/round10]: create an iterator which rounds each iterated value to the nearest power of 10 on a linear scale. - [`iterRound2( iterator )`][@stdlib/math/iter/special/round2]: create an iterator which rounds each iterated value to the nearest power of two on a linear scale. - [`iterRsqrt( iterator )`][@stdlib/math/iter/special/rsqrt]: create an iterator which iteratively computes the reciprocal (inverse) square root. - [`iterSignum( iterator )`][@stdlib/math/iter/special/signum]: create an iterator which iteratively evaluates the signum function. - [`iterSin( iterator )`][@stdlib/math/iter/special/sin]: create an iterator which iteratively computes the sine. - [`iterSinc( iterator )`][@stdlib/math/iter/special/sinc]: create an iterator which computes the normalized cardinal sine for each iterated value. - [`iterSinh( iterator )`][@stdlib/math/iter/special/sinh]: create an iterator which evaluates the hyperbolic sine for each iterated value. - [`iterSinpi( iterator )`][@stdlib/math/iter/special/sinpi]: create an iterator which computes the sine of each iterated value times π. - [`iterSpence( iterator )`][@stdlib/math/iter/special/spence]: create an iterator which evaluates Spence's function for each iterated value. - [`iterSqrt( iterator )`][@stdlib/math/iter/special/sqrt]: create an iterator which iteratively computes the principal square root. - [`iterSqrt1pm1( iterator )`][@stdlib/math/iter/special/sqrt1pm1]: create an iterator which computes `sqrt(1+x) - 1` for each iterated value. - [`iterTan( iterator )`][@stdlib/math/iter/special/tan]: create an iterator which evaluates the tangent for each iterated value. - [`iterTanh( iterator )`][@stdlib/math/iter/special/tanh]: create an iterator which evaluates the hyperbolic tangent for each iterated value. - [`iterTrigamma( iterator )`][@stdlib/math/iter/special/trigamma]: create an iterator which evaluates the trigamma function for each iterated value. - [`iterTrunc( iterator )`][@stdlib/math/iter/special/trunc]: create an iterator which rounds each iterated value toward zero. - [`iterTrunc10( iterator )`][@stdlib/math/iter/special/trunc10]: create an iterator which rounds each iterated value to the nearest power of 10 toward zero. - [`iterTrunc2( iterator )`][@stdlib/math/iter/special/trunc2]: create an iterator which rounds each iterated value to the nearest power of two toward zero. - [`iterVercos( iterator )`][@stdlib/math/iter/special/vercos]: create an iterator which computes the versed cosine for each iterated value. - [`iterVersin( iterator )`][@stdlib/math/iter/special/versin]: create an iterator which computes the versed sine for each iterated value.
## Examples ```javascript var objectKeys = require( '@stdlib/utils/keys' ); var ns = require( '@stdlib/math/iter/special' ); console.log( objectKeys( ns ) ); ```