- #1
Joel_662
- 1
- 0
Hey,
So I am fairly new to Mathematica (and the physics forums too). I am having a problem with mathematica not calculating the numeric result to an very complex integral. My question is, how do I force it to evaluate the integral as a number? I'm assuming that the integral of a square root is possible in mathematica as i checked the help files and it seems to suggest it is. I have tried the evaluation both with and without using n[A] which seems to be the suggested method of forcing a numeric evaluation.
K=1
R=1
VM=1
L=1
radius=1
z=-0.000000*x^6 - 0.000000*x^5 + 0.000049*x^4 + 0.000115*x^3 - 0.018528*x^2 - 0.033042*x + 2.964166
dzdx=D[z,x]
absdzdx=Abs[dzdx]
sqrtfactor=Sqrt[1+dzdx^2]
A=2*Pi*K*R*VM*L*(Integrate[(6.5+4.56*(absdzdx)+0.654*(absdzdx)^2)*x*sqrtfactor,{x,0,r}])*((2*Pi*\!\(
\*SubsuperscriptBox[\(\[Integral]\), \(0\), \(r\)]\(\((x*sqrtfactor)\) \[DifferentialD]x\)\))/10000)
I have tried to break up the calculations so that mathematica doesn't take to long to calculate it but it still seems to take at least 3 or 4 mins of running before it displays an answer. The variables do unfortunately need to stay separate as they will be changed. I apologise in advance if it is just some stupid error of mine.
So I am fairly new to Mathematica (and the physics forums too). I am having a problem with mathematica not calculating the numeric result to an very complex integral. My question is, how do I force it to evaluate the integral as a number? I'm assuming that the integral of a square root is possible in mathematica as i checked the help files and it seems to suggest it is. I have tried the evaluation both with and without using n[A] which seems to be the suggested method of forcing a numeric evaluation.
K=1
R=1
VM=1
L=1
radius=1
z=-0.000000*x^6 - 0.000000*x^5 + 0.000049*x^4 + 0.000115*x^3 - 0.018528*x^2 - 0.033042*x + 2.964166
dzdx=D[z,x]
absdzdx=Abs[dzdx]
sqrtfactor=Sqrt[1+dzdx^2]
A=2*Pi*K*R*VM*L*(Integrate[(6.5+4.56*(absdzdx)+0.654*(absdzdx)^2)*x*sqrtfactor,{x,0,r}])*((2*Pi*\!\(
\*SubsuperscriptBox[\(\[Integral]\), \(0\), \(r\)]\(\((x*sqrtfactor)\) \[DifferentialD]x\)\))/10000)
I have tried to break up the calculations so that mathematica doesn't take to long to calculate it but it still seems to take at least 3 or 4 mins of running before it displays an answer. The variables do unfortunately need to stay separate as they will be changed. I apologise in advance if it is just some stupid error of mine.