floor

学习PHP几个数学计算的内部函数

心已入冬 提交于 2019-12-29 12:20:55
简介:这是学习PHP几个数学计算的内部函数的详细页面,介绍了和php,有关的知识、技巧、经验,和一些php源码等。 class='pingjiaF' frameborder='0' src='http://biancheng.dnbcw.info/pingjia.php?id=342968' scrolling='no'> 下面主要讲述 round, floor, ceil, pow, rand,max, min, decbin, bindec, dechex, hexdec, decoct, octdec 函数。 round round - 对浮点数进行四舍五入。round 函数语法如下: round(float,precision) 其中参数 precision 表示小数点后面要保持的精度位数。如果不写参数 precision,表示四舍五入到整数位,比如: echo round(3.4); // 3echo round(3.5); // 4echo round(3.6); // 4 如果 precision 为2,表示四舍五入到小数点后2位。示例如下: echo round(1.95583, 2); // 1.96 如果参数 precision 为负数,表示四舍五入到小数点前。比如: echo round(1241757, -3); // 1242000 floor floor

mysql中floor函数的作用是什么?

痴心易碎 提交于 2019-12-27 07:27:25
需求描述 :   最近写mysql程序的时候,使用了floor函数,在此记录下该函数的作用 操作过程 : 1.使用floor函数的测试 mysql> select floor(1.23),floor(-1.23); +-------------+--------------+ | floor(1.23) | floor(-1.23) | +-------------+--------------+ | 1 | -2 | +-------------+--------------+ 1 row in set (0.00 sec) 备注:根据官方文档的提示,floor函数返回 小于等于 该值的最大整数. 示意图 : 官方文档参考 : FLOOR(X) Returns the largest integer value not greater than X. mysql> SELECT FLOOR(1.23), FLOOR(-1.23); -> 1, -2 For exact-value numeric arguments, the return value has an exact-value numeric type. For string or floating-point arguments, the return value has a floating-point type.

Python数据处理(四舍五入、除法部分)

风格不统一 提交于 2019-12-26 08:38:26
本文转载自: https://www.cnblogs.com/junyiningyuan/p/5338378.html 作者:junyiningyuan 转载请注明该声明。 最近在改造之前的代码的过程中发现一直使用的除法都是“传统除法”,即对整数进行操作,结果的精度不准,正巧在看 数据处理 +四舍五入+除法部分+.html' target='_self'>python核心编程,碰到这块,整理下。 关于除法 传统除法 对两个整数进行除的运算,同时结果会舍去小数部分,返回一个整数。但如果操作数之一是浮点型,则执行真正的除法。 真正的除法 返回真实的商,不管操作数的类似是整数还是浮点数 需要执行如下指令将传统除法转换为真正的除法 from __future__ import division 地板除 不管操作数为何种数值类型,总是舍去小数部分,返回数字序列中比真正的商小的最接近的数字,操作符“//” 举例: >>> print "5/3传统除法:",5/3 5/3传统除法: 1 >>> from __future__ import division >>> print "5/3真正的除法:",5/3 5/3真正的除法: 1.66666666667 >>> print "5/3地板除:",5.0//3 5/3地板除: 1.0    关于取整 常用的直接就是int()

Use if statement against the ones place decimal value in Excel

泄露秘密 提交于 2019-12-25 02:17:14
问题 I need help creating a formula that rounds a number with a 1 or 6 in the ones place down to the nearest multiple of 5 (e.g., 276 to 275 or 131 to 130) and rounds any other number up to the nearest multiple of 5 (e.g., 277 to 280 or 132 to 135). I figured the logic would look something like this: =if(can't figure out this condition, ceiling(A1,5), floor(A1,5)) 回答1: You can use MROUND instead: =MROUND(A1,5) It rounds to the nearest 5. Anything including and above 277.5 will be rounded to 280,

简单好用threejs库3D可视化试一下?

↘锁芯ラ 提交于 2019-12-24 04:20:29
3D可视化应用开发对每个企业来说都是大工程,需要投入大量的人力物力财力才能做好这项工程,但其实可是化繁为简,不需要大费周章,具体来说,thingjs3D可视化开发平台,基于webgl3D绘制标准,使用最热门的Javascript语言,封装 threejs库 ,前端工程师可实现在线开发,可视化场景通过拖拽和简单写一些代码,对接数据源,项目部署之后就可以运行在您的服务器了~真是简单好用呢。 thingjs-面向物联网的3D可视化开发平台 /** * 说明:将场景中对象展示到界面上 * 操作:点击界面上选择框 * 说明:场景初始化完成后,子物体的显隐、样式默认继承父物体的显隐状态、样式 * 通过 obj.inheritVisible = true/false 控制子物体是否继承父物体显隐状态 */ // 引入jquery.easyui插件 THING.Utils.dynamicLoad(['lib/jquery.easyui.min.js', 'lib/default/easyui.css'], function() { var panel = `<div class="easyui-panel" style="opacity: 0; padding:5px; width: 300px;height: auto;margin-top: 10px;margin-left: 10px;

干货分享 -- Math

邮差的信 提交于 2019-12-23 17:55:53
昼猫笔记 JavaScript -- Math Math也是JS的内置对象,但是它不是一个构造函数,它属于一个工具类不用创建对象,它封装了数学运算相关的属性和方法,今天就来写下常用的函数【API(application progrom interface 应用程序开发接口)】 常用属性 PI 表示的圆周率 常用方法 abs() 可以用来计算一个数的绝对值 console.log(Math.abs(-1)) // 1 round() 四舍五入取整 console.log(Math.round(3.22)) // 3 ceil() 向上取整,获取最接近的整数(大于或者等于当前数字) console.log(Math.ceil(3.000022)) // 4 console.log(Math.ceil(3)) // 3 floor() 向下取整 console.log(Math.floor(3.22)) // 3 max() 取最大值 console.log(Math.max(3,4,6,7,2,1,4,0)) // 7 min() 取最小值 console.log(Math.min(3,4,6,7,2,1,4,0)) // 0 获取数组中最大数,最小数 var arr = [3, 4, 6, 7, 2, 1, 4, 0] console.log(Math.max.apply(null,

Why does Binary search algorithm use floor and not ceiling - not in an half open range

我们两清 提交于 2019-12-22 04:43:14
问题 When we have an array with indexes from 0 to n for example. when I use the Binary search using floor or ceiling when calculating the middle index I get the same out put. int middle = ceiling ((left+right)/2); Is there a reason using floor over ceiling ? what bug will happen using the ceiling ? 回答1: There's no difference in complexity. Both variants are log(n). Depending on the rest of your implementation, you may get a different result if your array looks for instance like 0 1 1 1 1 2 and

Why does Binary search algorithm use floor and not ceiling - not in an half open range

ⅰ亾dé卋堺 提交于 2019-12-22 04:43:12
问题 When we have an array with indexes from 0 to n for example. when I use the Binary search using floor or ceiling when calculating the middle index I get the same out put. int middle = ceiling ((left+right)/2); Is there a reason using floor over ceiling ? what bug will happen using the ceiling ? 回答1: There's no difference in complexity. Both variants are log(n). Depending on the rest of your implementation, you may get a different result if your array looks for instance like 0 1 1 1 1 2 and

Revit二次开发之梁随板

扶醉桌前 提交于 2019-12-22 03:23:49
Revit二次开发之梁随板 这个demo实现了梁随斜板的功能: using System ; using System . Collections . Generic ; using System . Linq ; using System . Text ; using System . Threading . Tasks ; using Autodesk . Revit . DB ; using Autodesk . Revit . UI . Selection ; using Autodesk . Revit . UI ; using Autodesk . Revit . Attributes ; namespace 梁随板 { [ Autodesk . Revit . Attributes . Transaction ( TransactionMode . Manual ) ] [ Autodesk . Revit . Attributes . Regeneration ( RegenerationOption . Manual ) ] [ Autodesk . Revit . Attributes . Journaling ( JournalingMode . UsingCommandData ) ] public class Command :

Avoiding Calls to floor()

帅比萌擦擦* 提交于 2019-12-20 12:27:31
问题 I am working on a piece of code where I need to deal with uvs (2D texture coordinates) that are not necessarily in the 0 to 1 range. As an example, sometimes I will get a uv with a u component that is 1.2. In order to handle this I am implementing a wrapping which causes tiling by doing the following: u -= floor(u) v -= floor(v) Doing this causes 1.2 to become 0.2 which is the desired result. It also handles negative cases, such as -0.4 becoming 0.6. However, these calls to floor are rather