Hello. I am trying to calculate the vector X as shown in the attached file. But I don’t know what commands to use. Can you give me information about this?
Untitled-5.nb (15.3 KB)
-
N is a Mathematica-Symbol. Look it up in the Help-Section. You shouldn’t use N, try vN or so.
-
Your “N” clearly is a vector of dimension 3. But your H is a scalar. Tell me , why should
scalar / vector
an operation that is - at least - not well (if not far from ) defined be a vector? Did you mean N / H ?
Dear Hans,
May I have your email address, please?
Yes:
First of all, thank you for your reply. There are vectors N and X such that <N, X> = H. Actually, I’m trying to find the possible values of the X vector. How do I calculate with Mathematica?
I think you mean this
( < vecN , vecX > = H = prod in this code )
vecN = {a, b, c};
vecX = {x1, x2, x3};
scalar = s;
prod = vecN.vecX;
lsg=Solve[prod == scalar, x1] // Flatten
Then x1 is given as function of x2 and x3. Chose any x2 and x3, calculate x1 and this vector gives your condition.
vecX1 = vecX /. lsg
vecN.vecX1
These are exactly the codes I’m looking for. Thank you very much for your help.
Can we divide two vectors? Can we divide Zantrex Black two vector quantities? For eg., Pressure( a scalar) equals force (a vector) divided by area (a vector).
No. There is not an operation like vector / vector.
By the way, pressure in general is NOT a scalar, but a Tensor:
press = {
{pxx, pxy, pxz},
{pyx, pyy, pyz},
{pzx, pzy, pzz}
};
and the force experienced by a surface ( given by a vector surf = { sx,sy, sz } is given by
force = press.surf
Often the off-diagonal elements of press are 0 (this is most likely not the case in vsicous fluids) , and if in addition the diagonal elements are equal = p ( an isotropic medium) the force points in the direction of surf. Then you can write
p = Norm[ force ] / Norm[ surf ]
press = {
{p, 0, 0},
{0, p, 0},
{0, 0, p}
};
f1 = press.{1, 1, 1}
f2 = press.{2, 3, 4}
Norm[f1]/Norm[{1, 1, 1}]
Norm[f2]/Norm[{2, 3, 4}]
Gradient_OP_f_CP_.nb (21.1 KB)
Hello. Although I selected the s value differently in these two files, the same result came out. I couldn’t understand the reason. I wonder if the results I get are correct. Where do you think I might have made a mistake?
s=+1…nb|attachment (68.9 KB)
s=-1…nb|attachment (68.9 KB)
Hmmm. These notebooks don’t run on my system. What exactly is your question?
In the equation <N, X> = H, I try to find the vector X. When I change the scalar value “H” here, the result (the vector X) also needs to change. But Mathematica gives the same result. Its stuck on my mind. I wonder where I made a mistake.
In the equation <N, X> = H, I try to find the vector X. When I change the scalar value “H” here, the result (the vector X) also needs to change. But Mathematica gives the same result. Its stuck on my mind. I wonder where I made a mistake.
Where is your H?
And you write
s = 1/4 ( Abs[ Sin[ b s ] +......
So s appears on both sides of the = sign, I wonder that you don’t get error messages.
What about this?
s=+1… _OP_1_CP_.nb|attachment (85.3 KB)
Actually, what I want to ask is exactly like this: Here I have changed the sign at the end of the parenthesis (shown in green). I thought the result would also change. But it has not changed. I couldn’t understand why.
s=+1…nb|attachment (61.5 KB)
s=-1…nb|attachment (61.8 KB)
Dear Meryem,
I must admit I don’t understand exactly what you mean.
As your expressions in fact aren’t simple I decided to do some numerical calculations (see notebook). For this purpose I defined an arbitrary function gg to be inserted for g later on.
With several calculations I obtained different solutions for x1 using + or - in H.
Note: the two different solution - vectors differ only in the x1-component by a constant.
s=new+1…nb|attachment (85.9 KB)