A brief discussions on derivative and the"Gradient"
H.Tahsiri
Vector Gradient
H.Tahsiri
<<Calculus`VectorAnalysis` <<Graphics`PlotField3D` <<Graphics`PlotField` <<Graphics`Graphics3D`
u=y^2-x 2 -x + y
grd=Grad[u,Cartesian] {-1, 2 y, 0}
g1=PlotGradientField[u,{x,-3,3},{y,-3,3},PlotPoints->10];
g=Plot3D[u,{x,-3,3},{y,-3,3},Axes->Automatic, PlotPoints->25,Shading->False]
c=ContourPlot[u,{x,-3,3},{y,-3,3},ContourShading->False, Contours->10,PlotPoints->30];
Show[g1,c];
s=grd.grd 2 1 + 4 y
norm=grd/Sqrt[s] 1 2 y {-(--------------), --------------, 0} 2 2 Sqrt[1 + 4 y ] Sqrt[1 + 4 y ]
Clear[x,y,z,u]
u2=17x-2x y/z+y^2 z^3 2 x y 2 3 17 x - ----- + y z z
gradu2=Grad[u2,Cartesian] 2 y -2 x 3 2 x y 2 2 {17 - ---, ---- + 2 y z , ----- + 3 y z } z z 2 z
g3=PlotGradientField3D[ u2,{x,-1,1},{y,-1,1},{z,1,2}, VectorHeads->True,PlotPoints->3,Axes->Automatic];
Show[g3,ViewPoint->{-4.000, -4.000, 4.000},Axes->Automatic]
PlotVectorField[{-x,y},{x,-1,1},{y,-1,1}];
PlotVectorField[{x,0},{x,-1,1},{y,-1,1},PlotPoints->7, Axes->True];
PlotVectorField[{0,y},{x,-1,1},{y,-1,1},PlotPoints->7, Axes->True];
PlotVectorField[{x,-y},{x,-1,1},{y,-1,1},PlotPoints->7, Axes->True];
PlotVectorField[{-x,-y},{x,-1,1},{y,-1,1},PlotPoints->7, Axes->True];
<<Graphics`PlotField3D`
PlotVectorField3D[{x,y,z},{x,-1,1},{y,-1,1},{z,-1,1}, VectorHeads->True,PlotPoints->4,Boxed->False,Axes->True];