Because I need to use php to generate 0~1 random decimals for my work, I wrote an article before "php method to generate 0~1 random decimals", based on mt_rand() and mt_getrandmax()accomplish.
Later some netizens commented that the PHP native method lcg_value() can generate random decimals from 0 to 1.
float lcg_value ( void )
lcg_value() returns a pseudo-random number in the range (0, 1). This function combines two congruential generators with periods 2^31 - 85 and 2^31 - 249. The period of this function is equal to the product of these two prime numbers.
Return: pseudo-random number in the range (0, 1).
Output:
0.11516515851995 0.064684551575297 0.68275174031189 0.55730746529099 0.70215008878091
The running time of executing 100,000 times based on mt_rand() and mt_getrandmax() algorithms
Output: run time 266.893148 ms
Running time of executing lcg_value() 100,000 times
Output: run time 86.178064 ms
Execution time comparison, because lcg_value() is directly a native PHP method, and mt_rand() and mt_getrandmax() need to call two methods and need to be calculated, so The execution time of lcg_value() is about 3 times faster.
Random effect based on mt_rand() and mt_getrandmax() algorithms
=0.5){ imagesetpixel($im, $x, $y, $color1); }else{ imagesetpixel($im, $x, $y, $color2); } } } imagepng($im); imagedestroy($im);?>
Random effect diagram:
##Random effect of lcg_value()
=0.5){ imagesetpixel($im, $x, $y, $color1); }else{ imagesetpixel($im, $x, $y, $color2); } } } imagepng($im); imagedestroy($im);?>
Comparing the random effects, it can be seen that using mt_rand() and mt_getrandmax( ) algorithm generates random effects that are out of order, and the random effects are better than lcg_value().
This article explains the comparison of the effects of generating 0~1 random decimals between php lcg_value and mt_rand. For more related content, please pay attention to the php Chinese website.
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