How to implement Trapezoidal Integration with Infinite Limits in C? -

-

i trying create c program integrate sin(x)/sqrt(x) between 0 , infinity. using trapezium rule cutting off end points function tends infinity.

however total returned high , not sure why. here's code:

#include<math.h> #include<stdio.h>  double func(double u) { double a;   = ((sin(u))/(sqrt(u)));   return a;}  void main()     {     int i, n;     double sum, u, a, b, h, fa, fb, f;      printf("enter value of n\n");     scanf("%d" ,&n);      a=0.01;     b=1000;      h=(b-a)/(n-1);      sum=0;     f=func(a);     u=a;      for(i=0; i<n; i++)     {             sum=sum+f;             u=u+h;             f=fabs(func(u));     }      fa=func(a);     fb=func(b);      sum=sum-(0.5*fa)-(0.5*fb);     sum=sum*h;      printf("i: %lf\n", sum); }

any thoughts?

working example: http://ideone.com/xibrov

just remove fabs in line f=fabs(func(u));.

and should use int main(void) , return 0; @ end instead of void main().


Comments

Post a Comment

Popular posts from this blog

node.js - Mongoose: Cast to ObjectId failed for value on newly created object after setting the value -

-
this question has answer here: what's mongoose error cast objectid failed value xxx @ path “_id”? 7 answers even though has been asked many times because entity has no valid objectid field. i came across situation objectid set value can casted objectid still error. the schema: var serviceschema = parammongoose.schema({ servicename:{ type: parammongoose.schema.types.objectid , ref: 'servicenames',required:true } }); pseudo code: servicefromdb=new service({servicename:'some name'}); servicefromdb.servicename='000000000000000000000001'; servicefromdb.save(function(paramerror,paramdata){ if(paramerror){ console.log('but but...',servicefromdb,paramerror) } }); the output of code is: but but... { servicename: 000000000000000000000001, _id: 55079a90286f49280364f78b } { [casterror: cast objectid faile...
Read more

gradle error "Cannot convert the provided notation to a File or URI" -

-
i have defined 2 system properties in gradle.properties: systemprop.builddir=build systemprop.cfgdir=build\\cfg and have following task defined in build.gradle: task clean(group:'clean',description:'clean project') << { ant.sequential { delete(dir: system.properties.builddir) mkdir(dir: system.properties.builddir) delete(dir: system.properties.cfgdir) mkdir(dir: system.properties.cfgdir) } } this generates following error: execution failed task ':clean'. > cannot convert provided notation file or uri: {dir=build}. following types/formats supported: - string or charsequence path, e.g 'src/main/java' or '/usr/include' - string or charsequence uri, e.g 'file:/usr/include' - file instance. - uri or url instance. but equivalent block of code not generate error , works expected: task clean(group:'clean',description:'clean project') << { ...
Read more

ios - Possible to get UIButton sizeThatFits to work? -

-
i have been using method of resizing uibuttons depreciated, , not robust. , other reasons, want sizethatfits work uibuttons. i've read online, i'm not sure if should work (seems working some, not others, difference maybe between style, i'm using custom). here simple test code recreate issue (i put in viewdidload test, shouldn't matter, , real code part of large project): uibutton *btn = [uibutton buttonwithtype:uibuttontypecustom]; [btn settitle:@"this test long title need word wrap more single line when displayed on tiny ipod in portrait view." forstate:uicontrolstatenormal]; btn.titlelabel.linebreakmode = uilinebreakmodewordwrap; // depreciated - nothing replace it? cgrect r = btn.frame; r.origin.x = 0; r.origin.y = 0; r.size.width = 320; r.size.height = [btn.titlelabel.text sizewithfont:btn.titlelabel.font constrainedtosize:cgsizemake(r.size.width,100000) linebreakmode:btn.titlelabel.linebreakmode].height; // returns approx 86 , changes correctly ...
Read more