manusia

...ga ada yg bener nih ah jawabannya.
masalahnya dah tau di double precision sih dari awal.
cm ga tau solusinya.
casting ke int  = solusi pertama, tp gagal kalo range Bu ama bv sangat random, ex: 1e-30,etc.
solusi kedua ga tau. nunggu ide.
solusi ketiga, jgn pake c++, pake matlab. sayangnya req pake c++.

int _tmain(int argc, _TCHAR* argv[])
{
double Bux = 1.444, Buy =2.3232, Buz =3.23232;
double bvx = -1.543, bvy = -2.5343, bvz = -3.5343;
double Bvx,Bvy,Bvz;
if((Bux*bvx+Buy*bvy+Buz*bvz)==0)
{
Bvx = bvx; Bvy = bvy; Bvz = bvz;
}
else
{
double k = -1 * (Bux*bvx+Buy*bvy+Buz*bvz) / (pow(Bux,2)+pow(Buy,2)+pow(Buz,2));
Bvx = (k*Bux)+bvx;
Bvy = (k*Buy)+bvy;
Bvz = (k*Buz)+bvz;
double dot_product = Bux*Bvx+Buy*Bvy+Buz*Bvz;

//kenapa dot_product harus nol
//dot_product = Bux * ((k*Bux)+bvx) + Buy*((k*Buy)+bvx)+ Buz*((k*Buz)+bvz)
//                = k (Bux^2+Buy^2+Buz^2) + (Bux*bvx+Buy*bvy+Buz*bvz)
//masukin k = -1 * (Bux*bvx+Buy*bvy+Buz*bvz) / (pow(Bux,2)+pow(Buy,2)+pow(Buz,2))
//                = 0

double g =3;
}
return 0;
}

>>7
bagaimana kalo mu cast ke int setelah itung dot productnya? bolehkah seperti itu?

>>8
sayangnya, yg diinginkan adalah nilai (double) Bu dan Bv di mana Bu (dot) Bv = 0.
dot_product cuma buat confirm hasil. jd ga ada guna cast int ke dot_product.
makasih dah kasih ide, walau idenya dah kepikir jg.

>>9
OOOOOOOOOOOOOOOOOOOOO, adu baru sadar, kok bodoh amat ga ngarti maksudmu aslinya apaan.

baiklah akan kubantu pikir lagi, tanya: ini pr kah? ato mu iseng2 aja? :D

>>10
anggeplah pr kecil dari pr yg amat besar :D

karena ga ada yg jawab2 jg. Mari mulai pertanyaan baru

How to subdivide regular pentagon into smaller regular pentagons?
We know it's a trivial matter to subdivide equilateral triangle into 3 smaller equilateral triangles. It's just a matter of finding an intersection of edges formed by connecting half or center points of one edges to the opposite points.
Any kind help is appreciated.

>>12
Will that method produce *3* *equilateral* triangles?

Wah hebat, bisa notice salahnya di sana.
Hasilnya pake method itu cm akan jd kongruen.

jd, mari diulang:
How to subdivide regular pentagon into smaller regular pentagons?
We know it's a trivial matter to subdivide equilateral triangle into '4' smaller equilateral triangles.
It's just a matter of forming edges between each center pts of all the edges.

Aplikasi dari subdivision of triangles: buat subdivide icosahedron
void subdivide(float *v1, float *v2, float *v3)
{
GLfloat v12[3], v23[3], v31[3];
GLint i;
for (i = 0; i < 3; i++) {
v12[i] = v1[i]+v2[i];
v23[i] = v2[i]+v3[i];
v31[i] = v3[i]+v1[i];
}
normalize(v12);
normalize(v23);
normalize(v31);
drawtriangle(v1, v12, v31);
drawtriangle(v2, v23, v12);
drawtriangle(v3, v31, v23);
drawtriangle(v12, v23, v31);
}

Point pertanyaan: cari cara termudah buat subdivide dodecahedron tanpa dissamble pentagons jadi triangles.