# Category: Mathematica

## Interpreting P-Value on ParameterTable

When using LinearModelFit[] we can generate a table of parameter values and statistics for the corresponding model using the property “ParameterTable”. Looking in the documentation I can’t find an explicit statement of the hypothesis test being performed for the p-values listed in this table. I would like to make sure …

## FindMinimum function does not produce minimum from near point

Using my simple program and I would like to find such matrix elements that minimize difference of their eigenvalues. H1 = {{1, 2}, {3, 4}}; H2 = {{2, 2}, {3, 2}}; f1[R_, S_] := R*H1 + S*IdentityMatrix[2] f2[R_, S_] := S*H2 + R*IdentityMatrix[2] Evl1 = N[Eigenvalues[f1[R, S]]]; Evl2 = N[Eigenvalues[f2[R, …

## Animation of a plane wave

I want to animate in 3D the plane wave sin(ωt+kx+ϕ)sin(ωt+kx+ϕ)\sin(\omega t+kx+\phi), but following the form from the documentation, I can only make kkk or ωω\omega vary, and I want ttt to change. How do I do that? ================= 1 Welcome! Please do add more info, especially your code. Consider …

## How to Fit experimental data with 4D ParametricNDSolve?

Let me first explain the background problem. I’m trying to solve a problem with a projectile motion in 4D such that the position vector is: r(t)=r[x(t),y(t),z(t)]\boldsymbol{r}(t)=\boldsymbol{r}[x(t),y(t),z(t)] I have the differential equations with F(t)=mr″(t)F(t)=mr”(t) such that: \boldsymbol{F}_{drag}(t)=\frac{1}{2} \rho A C_{drag} R (\boldsymbol{r’}(t))^2; \\ \boldsymbol{F}_{grav}=m\boldsymbol{g};\\ \boldsymbol{F}_{total}(t)=\boldsymbol{F}_{drag}(t)+\boldsymbol{F}_{grav}\boldsymbol{F}_{drag}(t)=\frac{1}{2} \rho A C_{drag} R (\boldsymbol{r’}(t))^2; \\ …