{
printf("This simple macro tests the TThreeVec class in interpreter mode.\n");
printf("The macro will test *some* of the vector operations supported.\n");
printf("==========================================\n");
printf("Created a TThreeVec (3,4,0). Is it's length 5?\n");
TThreeVec v1(3,4,0);
Float_t length_v1 = v1.norm();
printf("The length of TThreeVec v1 is %f.\n",length_v1);
v1.normalize();
printf("v1 has now been normalized. It had better be (0.6,0.8,0).\n");
printf("It is in fact ( %f , %f , %f )\n",v1[0],v1[1],v1[2]);
printf("==========================================\n");
printf("The inside cover of JD Jackson's Classical Electrodynamics has");
printf(" 3 vector formulas.\nLet's try them out.\n");
TThreeVec a(45,87,102);
TThreeVec b(5,-1024,19);
TThreeVec c(-19,7,5);
TThreeVec d(-123,-654,3.1E5);
printf("a = (%f,%f,%f)\n",a[0],a[1],a[2]);
printf("b = (%f,%f,%f)\n",b[0],b[1],b[2]);
printf("c = (%f,%f,%f)\n",c[0],c[1],c[2]);
printf("d = (%f,%f,%f)\n",d[0],d[1],d[2]);
printf("a dot (b cross c) ?= b dot (c cross a) ?= c dot (a cross b)\n");
Float_t first = a.dot(b.cross(c));
Float_t second = b.dot(c.cross(a));
Float_t third = c.dot(a.cross(b));
printf(" %f ?= %f ?= %f \n",first,second,third);
printf("==========================================\n");
printf(" a cross (b cross c) ?= (a dot c)b - (a dot b)c \n");
TThreeVec lhs = a.cross(b.cross(c));
// Checking for commutation in scaler muliplication
// The line for rhs1 works. The line for rhs2 doesn't. Will fix before
// issuing code.
TThreeVec rhs1 = b*(a.dot(c)); // vector times scalar works.
TThreeVec rhs2 = (a.dot(b))*c; // scalar times vector fails.
TThreeVec rhs = rhs1 - rhs2;
printf("(%f , %f , %f) ?= (%f , %f , %f)\n",lhs[0],lhs[1],lhs[2],rhs[0],rhs[1],rhs[2]);
printf("==========================================\n");
printf("(a cross b) dot (c cross d) ?= (a dot c)(b dot d) - (a dot d)(b dot c)\n");
first = (a.cross(b)).dot(c.cross(d));
second = (a.dot(c)) * (b*d) - (a*d) * (b.dot(c));
printf("%f &= %f\n",first,second);
printf("==========================================\n");
printf("Test macro done.\n");
}
There are many shortcuts in the class. Vectors can be comraed with >, <;
they can be compared to Float_ts with <, >, ==. (It is there lengths in
both cases being compared.
It is a very nice class, which I can say because I didn't write it. I am
just taking on its rootification.
I will get the friend operators working next week and ship it to Fons for
testing and integration into root.
Chris
=================================================================
= =
= Chris Jillings =
= Department of Physics phone/voice mail: (613) 545-6000x4805 =
= Queen's University fax: (613) 545-6813 =
= Kingston, Ontario email: chris@sno.phy.queensu.ca =
= Canada, K7L 3N6 web: http://sno.phy.queensu.ca =
= =
=================================================================