# Ceil > Round a double-precision floating-point number toward positive infinity.
## Usage ```javascript var ceil = require( '@stdlib/math/base/special/ceil' ); ``` #### ceil( x ) Rounds a double-precision floating-point number toward positive infinity. ```javascript var v = ceil( -4.2 ); // returns -4.0 v = ceil( 9.99999 ); // returns 10.0 v = ceil( 0.0 ); // returns 0.0 v = ceil( NaN ); // returns NaN ```
## Examples ```javascript var randu = require( '@stdlib/random/base/randu' ); var ceil = require( '@stdlib/math/base/special/ceil' ); var x; var i; for ( i = 0; i < 100; i++ ) { x = (randu()*100.0) - 50.0; console.log( 'ceil(%d) = %d', x, ceil( x ) ); } ```
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## C APIs
### Usage ```c #include "stdlib/math/base/special/ceil.h" ``` #### stdlib_base_ceil( x ) Rounds a double-precision floating-point number toward positive infinity. ```c double y = stdlib_base_ceil( 3.14 ); // returns 4.0 ``` The function accepts the following arguments: - **x**: `[in] double` input value. ```c double stdlib_base_ceil( const double x ); ```
### Examples ```c #include "stdlib/math/base/special/ceil.h" #include int main() { double x[] = { 3.14, -3.14, 0.0, 0.0/0.0 }; double y; int i; for ( i = 0; i < 4; i++ ) { y = stdlib_base_ceil( x[ i ] ); printf( "ceil(%lf) = %lf\n", x[ i ], y ); } } ```