using?System;

namespace?MathLib.Algorithm.Image
{
????///?

????///?刻度生成
????///?

????public?class?DegreeScale
????{
????????///?

????????///?計(jì)算刻度
????????///?起始值必須小于結(jié)束值
????????///?

????????///?起始值
????????///?結(jié)束值
????????///?期望刻度數(shù)量，實(shí)際數(shù)接近此數(shù)
????????///?刻度起始值，須乘以間隔使用
????????///?刻度結(jié)束值，須乘以間隔使用
????????///?刻度間隔
????????public?static?void?CalcDegreeScale（double?start?double?end?int?expect_num?out?int?degree_start?out?int?degree_end?out?double?degree_gap）
????????{
????????????if?（start?>=?end）
????????????{
????????????????throw?new?Exception（“起始值必須小于結(jié)束值“）;
????????????}

????????????double?differ?=?end?-?start;
????????????double?differ_gap?=?differ?/?（expect_num?-?1）;//35?4.6?0.27

????????????double?exponent?=?Math.Log10（differ_gap）?-?1;//0.54?-0.34?-1.57?
????????????int?_exponent?=?（int）exponent;//0?0=>-1?-1=>-2
????????????if?（exponent??1e-8）
????????????{
????????????????_exponent--;
????????????}

????????????int?step?=?（int）（differ_gap?/?Math.Pow（10?_exponent））;//35?46?27????????????
????????????int[]?fix_steps?=?new?int[]?{?10?20?25?50?100?};
????????????int?fix_step?=?10;//25?50?25
????????????for?（int?i?=?fix_steps.Length?-?1;?i?>=?1;?i--）
????????????{
????????????????if?（step?>?（fix_steps[i]?+?fix_steps[i?-?1]）?/?2）
?????