# Special Functions > Standard library strided array special math functions.
## Usage ```javascript var ns = require( '@stdlib/math/strided/special' ); ``` #### ns Standard library strided array special math functions. ```javascript var special = ns; // returns {...} ``` The namespace contains the following strided array functions:
- [`absBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/abs-by]: compute the absolute value of each element retrieved from a strided input array via a callback function and assign each result to an element in a strided output array. - [`abs( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/abs]: compute the absolute value for each element in a strided array. - [`abs2By( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/abs2-by]: compute the squared absolute value of each element retrieved from an input strided array via a callback function. - [`abs2( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/abs2]: compute the squared absolute value for each element in a strided array. - [`acosBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/acos-by]: compute the arccosine of each element retrieved from an input strided array via a callback function. - [`acoshBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/acosh-by]: compute the hyperbolic arccosine of each element retrieved from an input strided array via a callback function. - [`acotBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/acot-by]: compute the inverse cotangent of each element retrieved from an input strided array via a callback function. - [`acothBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/acoth-by]: compute the inverse hyperbolic cotangent of each element retrieved from an input strided array via a callback function. - [`acovercosBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/acovercos-by]: compute the inverse coversed cosine of each element retrieved from an input strided array via a callback function. - [`acoversinBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/acoversin-by]: compute the inverse coversed sine of each element retrieved from an input strided array via a callback function. - [`ahavercosBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/ahavercos-by]: compute the inverse half-value versed cosine of each element retrieved from an input strided array via a callback function. - [`ahaversinBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/ahaversin-by]: compute the inverse half-value versed sine of each element retrieved from an input strided array via a callback function. - [`asinBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/asin-by]: compute the arcsine of each element retrieved from an input strided array via a callback function. - [`asinhBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/asinh-by]: compute the hyperbolic arcsine of each element retrieved from an input strided array via a callback function. - [`atanBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/atan-by]: compute the arctangent of each element retrieved from an input strided array via a callback function. - [`atanhBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/atanh-by]: compute the hyperbolic arctangent of each element retrieved from an input strided array via a callback function. - [`avercosBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/avercos-by]: compute the inverse versed cosine of each element retrieved from an input strided array via a callback function. - [`aversinBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/aversin-by]: compute the inverse versed sine of each element retrieved from an input strided array via a callback function. - [`besselj0By( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/besselj0-by]: compute the Bessel function of the first kind of order zero for each element retrieved from an input strided array via a callback function. - [`besselj1By( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/besselj1-by]: compute the Bessel function of the first kind of order one for each element retrieved from an input strided array via a callback function. - [`bessely0By( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/bessely0-by]: compute the Bessel function of the second kind of order zero for each element retrieved from an input strided array via a callback function. - [`bessely1By( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/bessely1-by]: compute the Bessel function of the second kind of order one for each element retrieved from an input strided array via a callback function. - [`binetBy( N, x, strideX, y, strideY, clbk[, thisArg] )`][@stdlib/math/strided/special/binet-by]: evaluate Binet's formula extended to real numbers for each element retrieved from an input strided array via a callback function. - [`cbrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/cbrt]: compute the cube root of each element in a strided array. - [`ceil( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/ceil]: round each element in a strided array toward positive infinity. - [`dabs( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dabs]: compute the absolute value for each element in a double-precision floating-point strided array. - [`dabs2( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dabs2]: compute the squared absolute value for each element in a double-precision floating-point strided array. - [`dcbrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dcbrt]: compute the cube root of each element in a double-precision floating-point strided array. - [`dceil( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dceil]: round each element in a double-precision floating-point strided array toward positive infinity. - [`ddeg2rad( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/ddeg2rad]: convert each element in a double-precision floating-point strided array from degrees to radians. - [`deg2rad( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/deg2rad]: convert each element in a strided array from degrees to radians. - [`dfloor( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dfloor]: round each element in a double-precision floating-point strided array toward negative infinity. - [`dinv( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dinv]: compute the multiplicative inverse for each element in a double-precision floating-point strided array. - [`dmskabs( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskabs]: compute the absolute value for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmskabs2( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskabs2]: compute the squared absolute value for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmskcbrt( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskcbrt]: compute the cube root for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmskceil( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskceil]: round each element in a double-precision floating-point strided array toward positive infinity according to a strided mask array. - [`dmskdeg2rad( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskdeg2rad]: convert each element in a double-precision floating-point strided array from degrees to radians according to a strided mask array. - [`dmskfloor( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskfloor]: round each element in a double-precision floating-point strided array toward negative infinity according to a strided mask array. - [`dmskinv( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskinv]: compute the multiplicative inverse for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmskramp( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskramp]: evaluate the ramp function for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmskrsqrt( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmskrsqrt]: compute the reciprocal square root for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmsksqrt( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmsksqrt]: compute the principal square root for each element in a double-precision floating-point strided array according to a strided mask array. - [`dmsktrunc( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/dmsktrunc]: round each element in a double-precision floating-point strided array toward zero according to a strided mask array. - [`dramp( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dramp]: evaluate the ramp function for each element in a double-precision floating-point strided array. - [`drsqrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/drsqrt]: compute the reciprocal square root for each element in a double-precision floating-point strided array. - [`dsqrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dsqrt]: compute the principal square root for each element in a double-precision floating-point strided array. - [`dtrunc( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/dtrunc]: round each element in a double-precision floating-point strided array toward zero. - [`floor( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/floor]: round each element in a strided array toward negative infinity. - [`inv( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/inv]: compute the multiplicative inverse for each element in a strided array. - [`ramp( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/ramp]: evaluate the ramp function for each element in a strided array. - [`rsqrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/rsqrt]: compute the reciprocal square root for each element in a strided array. - [`sabs( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sabs]: compute the absolute value for each element in a single-precision floating-point strided array. - [`sabs2( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sabs2]: compute the squared absolute value for each element in a single-precision floating-point strided array. - [`scbrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/scbrt]: compute the cube root of each element in a single-precision floating-point strided array. - [`sceil( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sceil]: round each element in a single-precision floating-point strided array toward positive infinity. - [`sdeg2rad( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sdeg2rad]: convert each element in a single-precision floating-point strided array from degrees to radians. - [`sfloor( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sfloor]: round each element in a single-precision floating-point strided array toward negative infinity. - [`sinv( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sinv]: compute the multiplicative inverse for each element in a single-precision floating-point strided array. - [`smskabs( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskabs]: compute the absolute value for each element in a single-precision floating-point strided array according to a strided mask array. - [`smskabs2( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskabs2]: compute the squared absolute value for each element in a single-precision floating-point strided array according to a strided mask array. - [`smskcbrt( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskcbrt]: compute the cube root for each element in a single-precision floating-point strided array according to a strided mask array. - [`smskceil( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskceil]: round each element in a single-precision floating-point strided array toward positive infinity according to a strided mask array. - [`smskdeg2rad( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskdeg2rad]: convert each element in a single-precision floating-point strided array from degrees to radians according to a strided mask array. - [`smskfloor( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskfloor]: round each element in a single-precision floating-point strided array toward negative infinity according to a strided mask array. - [`smskinv( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskinv]: compute the multiplicative inverse for each element in a single-precision floating-point strided array according to a strided mask array. - [`smskramp( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskramp]: evaluate the ramp function for each element in a single-precision floating-point strided array according to a strided mask array. - [`smskrsqrt( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smskrsqrt]: compute the reciprocal square root for each element in a single-precision floating-point strided array according to a strided mask array. - [`smsksqrt( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smsksqrt]: compute the principal square root for each element in a single-precision floating-point strided array according to a strided mask array. - [`smsktrunc( N, x, sx, m, sm, y, sy )`][@stdlib/math/strided/special/smsktrunc]: round each element in a single-precision floating-point strided array toward zero according to a strided mask array. - [`sqrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sqrt]: compute the principal square root of each element in a strided array. - [`sramp( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/sramp]: evaluate the ramp function for each element in a single-precision floating-point strided array. - [`srsqrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/srsqrt]: compute the reciprocal square root for each element in a single-precision floating-point strided array. - [`ssqrt( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/ssqrt]: compute the principal square root for each element in a single-precision floating-point strided array. - [`strunc( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/strunc]: round each element in a single-precision floating-point strided array toward zero. - [`trunc( N, x, strideX, y, strideY )`][@stdlib/math/strided/special/trunc]: round each element in a strided array toward zero.
## Examples ```javascript var objectKeys = require( '@stdlib/utils/keys' ); var ns = require( '@stdlib/math/strided/special' ); console.log( objectKeys( ns ) ); ```