24小时热门版块排行榜    

查看: 2250  |  回复: 14
当前只显示满足指定条件的回帖,点击这里查看本话题的所有回帖

dengwei_19

木虫 (著名写手)

铁齿金不换诚实可靠小郎君

[求助] 现在做到高斯函数的误差函数一步,又是一个方程不知道用matlab怎么写

求w,求详解!谢谢!!!
回复此楼
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dengwei_19

木虫 (著名写手)

送鲜花一朵
引用回帖:
4楼: Originally posted by dbb627 at 2012-04-13 14:19:25:
>> syms x
>> syms w;int(exp(-x^2),0,w)

ans =

(pi^(1/2)*erf(w))/2

>> syms w;int(exp(-x^2),0,-w)

ans =

-(pi^(1/2)*erf(w))/2
===========
>> fun=@(x)-5.4* ...

15楼2012-04-18 15:43:15
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 15 个回答

onesupeng

金虫 (职业作家)

【答案】应助回帖

感谢参与,应助指数 +1
这个matlab有点悬吧?我觉得自己编程序算恐怕更好呢
长期招收博士生,参见http://fsl-unsw.com
2楼2012-04-13 13:47:46
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dengwei_19

木虫 (著名写手)

铁齿金不换诚实可靠小郎君

引用回帖:
2楼: Originally posted by onesupeng at 2012-04-13 13:47:46:
这个matlab有点悬吧?我觉得自己编程序算恐怕更好呢

不会吧。。。。。没办法求吗?
3楼2012-04-13 13:53:05
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

dbb627

荣誉版主 (著名写手)

【答案】应助回帖

★ ★ ★ ★ ★ ★
感谢参与,应助指数 +1
dengwei_19: 金币+6, ★★★很有帮助 2012-04-13 14:36:22
dengwei_19: 回帖置顶 2012-04-13 15:40:01
>> syms x
>> syms w;int(exp(-x^2),0,w)

ans =

(pi^(1/2)*erf(w))/2

>> syms w;int(exp(-x^2),0,-w)

ans =

-(pi^(1/2)*erf(w))/2
===========
>> fun=@(x)-5.4*(pi^(1/2)*erf(10*2^0.5./x))/2-2.8*(pi^(1/2)*erf(40*2^0.5./x))/2+2.6;
>> x=0.1:0.1:100;
>> y=feval(fun,x);
>> plot(x,y)
>> [x,feval,flag]=fsolve(fun,80)

Equation solved.

fsolve completed because the vector of function values is near zero
as measured by the default value of the function tolerance, and
the problem appears regular as measured by the gradient.




x =

   81.4787


feval =

-9.0775e-010


flag =

     1

» 本帖已获得的红花(最新10朵)

The more you learn, the more you know, the more you know, and the more you forget. The more you forget, the less you know. So why bother to learn.
4楼2012-04-13 14:19:25
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[硕博家园] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +3 uFOAtb1CDngh 2026-09-02 9/450 2026-09-03 20:20 by jyNB2vrbdUpR
[考博] 找导师 +7 yuanjiabao 2026-08-29 8/400 2026-09-03 20:15 by yinnelly
[公派出国] 售SCI-T0P文章,我:8O.5.5.1.O.54,科目齐全,可+急 +4 ero8OE6tv9cu 2026-09-02 5/250 2026-09-03 20:09 by jyNB2vrbdUpR
[教师之家] 售SCI一区T0P文章,我:8.O55.1.O.54,科目全,可十急 +4 ero8OE6tv9cu 2026-09-02 9/450 2026-09-03 20:07 by jyNB2vrbdUpR
[基金申请] 面上没中,邀请各位路过的虫友分析一下分数 +3 jackleilei 2026-09-03 3/150 2026-09-03 19:13 by god_tian
[硕博家园] 售一区SCI文章T0P,我:8O.551.O54,科目全,可十急 +4 YLHlRHNwYkce 2026-09-02 8/400 2026-09-03 18:50 by jyNB2vrbdUpR
[考研] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +3 YLHlRHNwYkce 2026-09-02 7/350 2026-09-03 18:50 by jyNB2vrbdUpR
[找工作] 售SCI一区T0P文章,我:8O.55.1.O.54,科目全,可伽急 +4 YLHlRHNwYkce 2026-09-02 11/550 2026-09-03 18:42 by jyNB2vrbdUpR
[硕博家园] 售SCI一区文章,我:8.O.551.O.5.4,科目全,可伽急 +3 rFEsUBKXRll0 2026-09-02 6/300 2026-09-03 16:49 by T0rGB46095mJ
[找工作] 售SCI文章,我:8O.5.5.1O.54,科目全,可十急 +3 ero8OE6tv9cu 2026-09-02 8/400 2026-09-03 16:38 by T0rGB46095mJ
[硕博家园] 售SCI文章,我:8O.5.5.1O.54,科目全,可十急 +3 ero8OE6tv9cu 2026-09-02 5/250 2026-09-03 16:38 by T0rGB46095mJ
[考研] 售SCI一区T0P文章,我:8O.55.1.O.5.4,科目齐全,可+急 +3 ero8OE6tv9cu 2026-09-02 10/500 2026-09-03 16:27 by T0rGB46095mJ
[基金申请] 国社科又开始会评了,不知道这次命运如何 +10 雨打竹帘 2026-08-30 14/700 2026-09-03 13:17 by qsd10086
[教师之家] 售SCI一区文章,我:8.O.55.1.O.54,科目齐全,可伽急 +3 YLHlRHNwYkce 2026-09-02 8/400 2026-09-03 12:03 by T0rGB46095mJ
[基金申请] 面上函评意见出来了,像什么等级? 20+4 Tsingking1 2026-08-27 17/850 2026-09-01 19:51 by 超级无敌华子
[论文投稿] 小白求助 投论文要求的highlights应该如何写 5+3 l1963982152 2026-08-29 4/200 2026-09-01 09:04 by 北京莱茵编辑
[基金申请] 面上意见出来了 +12 黄鸟于飞Chao 2026-08-29 23/1150 2026-08-31 18:57 by 黄鸟于飞Chao
[基金申请] 中青基了要发朋友圈吗? +7 349506619 2026-08-28 7/350 2026-08-31 13:39 by 冼亮淀粉酶
[基金申请] 29号明天会评吗 +4 笨笨唐 2026-08-28 4/200 2026-08-31 09:30 by huixian257
[基金申请] 为什么到现在没收到通知? +5 tannykie 2026-08-29 5/250 2026-08-30 21:05 by purplejack
信息提示
请填处理意见